public class helloworld { public static void main(string[] args) { system.out.println("hello world!"); int a = 1; a=a 1; a=a 2; system.out.println("a is " a); a=a 3; //断点行 a=a 4; system.out.println("a is " a); } } (1). 编写以上程序,并运行。将运行结果截图提交。 (2). 将断点设置在第八行,查看变量a的值,提交此刻的屏幕截图。
在switch(expression)语句中,expression的数据类型不能是:
下面程序的运行结果为: public class conditional{ public static void main( string args[]){ int x = 4; system.out.println("value is " ( (x > 4) ? 99.99 : 9 )); } }
以下程序的编译运行结果为: public class test2 { public static void main(string args[]){ int i = 10; int j = 10; boolean b = false; if(b = i == j) //a行 system.out.println("true"); else system.out.println("false"); } }
假设a是int类型变量,并初始化为1,则下列哪个为合法的条件语句?
设有如下代码: public class ex2 { public static void main(string[] args) { int x = 0;int y = 0; outer: for (x = 0;x < 100;x ) middle: for(y = 0;y < 100;y ){ system.out.println("x=" x ";y=" y); if(y == 10){/*insert code*/} } } } 在“insert code”处插入什么代码可以结束所有循环?
以下程序的编译运行结果为: public class ex2 { public static void main(string[] args) { int total = 0; for(int i = 0,j = 10;total > 30; i,--j){ system.out.println("i = " i " ;j = " j); total = (i j); } system.out.println("total: " total); } }
以下程序段执行完后,i、j的值分别为: int i = 1,j = 10; do{ if(i >--j)continue; }while(i<5);
下面哪条语句存在语法错误:
下面哪条语句存在语法错误:
下面哪条语句存在语法错误:
下列字符串中,哪些是java的合法标志符?
下列字符串中,哪些是java的关键字?
有如下代码段: switch(a){ case 1:system.out.println("one");break; case 2: case 3:system.out.println("two");break; default:system.out.println("end"); } 变量a的取值是下列哪些情形时能使程序输出“two”。
关于以下程序哪条叙述正确: int j = 2; switch(j){ case 2: system.out.println("value is two"); case 2 1: system.out.println("value is three"); break; default: system.out.println("value is " j); break; }
下面不属于java基本数据类型的是:
请实现程序输出以下星塔。 * *** ***** *** * 需要在main函数的输入参数中设置5,输出5层星塔。如果是输入7,则是7层星塔。假设输入参数都是奇数,且都大于等于5,小于等于11。需要提交代码、(eclipse)设置参数截图、(eclipse)运行结果截图。
从键盘键入三个整数,然后按照从小到大的顺序将其输出。 需要提交代码、(eclipse)运行结果截图。
编写程序,输出九九乘法表。 需要提交代码、(eclipse)运行结果截图。
编写程序,输出从公元1900年到2100年所有闰年的年号,每输出5个年号换一行。判断年是否为闰年的条件是:① 若年号可以被4整除,而不能被100整除,则是闰年;② 若年号可以被400整除,也是闰年。 需要提交代码、(eclipse)运行结果截图。
水仙花数是指一个3位数,其个位、十位、百位上的数字的立方和等于该数本身,例如371=3的3次方 7的3次方 1的3三次方,因此371是一个水仙花数。编写程序,求所有的水仙花数。 需要提交代码、(eclipse)运行结果截图。
计算e=1 1/1! 2/2! …… n/n!。要求n由控制台输入,e精确到小数点后5位。 需要提交代码、(eclipse)运行结果截图。
完善三个数字对象排序程序。
有如下代码段: public static void booleantest() { int a = 1, b =1; if (a == b || b<0) a ; if (a <= 2 &&(!(b<0))) b=b<<1; system.out.println(a "," b); } 则运行结果为:
如下赋值语句中,有语法错误的是?
有如下类定义: public class rectangle { public int width = 3; public int height = 4; public int area() { return width * height; } } 则如下代码输出结果为: rectangle rectangle; rectangle.height = 5; system.out.println(rectangle.area());
执行如下代码片段后,i和n的值分别为: int i = 10; int n =( i ) % 5;
执行如下代码片段后,num的值为: int num = 5; num = (num % 2) == 0 ? num – 1 : num 1;
有如下代码段: if (num >= 0) if (num == 0) system.out.println("first string"); else system.out.println("second string"); system.out.println("third string"); 若num为3,则输出结果为:
下列变量名称中,不属于有效java变量命名的是?
对于java1.7及之后版本,如下不能用于switch的类型是:
如下对java基本类型的描述,错误的是?
如下循环结构中,输出结果与其它三组不一致的一组是:
swap方法定义如下: public static void swap(int num1, int num2) { int temp = num1; num1 = num2; num2 = temp; } 执行如下代码后, int num1 = 10; int num2 = 5; int num3 = 20; swap(num1, num2); swap(num2, num3); num1, num2, num3的值分别为:
number类定义如下: public class number { public int x; } swap方法定义如下: public static void swap(number number1, number number2) { int temp = number1.x; number1.x = number2.x; number2.x = temp; } 运行如下代码: number number1 = new number(); number number2 = new number(); number number3 = new number(); number1.x = 1; number2.x = 2; number3.x = 3; swap(number1, number2); swap(number2, number3); 则number1.x, number2.x, number3.x的值分别为:
假设有boolean变量flag1,flag2,则如下表达式中哪个不能代表异或逻辑?(异或逻辑:如果a、b两个值不相同,则异或结果为true。如果a、b两个值相同,异或结果为false。)
如下关于java类的说法,错误的是?
如下赋值语句,有编译错误的是?
下列关于main方法的描述中,错误的是?
java有“一次编译,到处运行”的说法,此种说法中编译的结果是:
下列不属于java基本数据类型的是?
如下关于jdk和jre的说法,错误的是?
在java中,下面对于构造函数的描述正确的是
assume i and j are member variables with double type in class x. in the following codes, which one is not right constructor? ( )
given: class cardboard { short story = 5; cardboard go(cardboard cb) { cb = null; return cb; } public static void main(string[] args) { cardboard c1 = new cardboard(); cardboard c2 = new cardboard(); cardboard c3 = c1.go(c2); c1 = null; // do stuff } } when // dostuff is reached, how many objects of cardboard are null?
given the uncompleted code of a class: class person { string name, department; int age; public person(string n){ name = n; } public person(string n, int a){ name = n; age = a; } public person(string n, string d, int a) { // doing the same as two arguments version of constructor // including assignment name=n,age=a department = d; } } which expression can be added at the "doing the same as..." part of the constructor?
given the following class class mynumber { private int num = 5; public mynumber(int num) { this.num = num; } public int getnum() { return num; } public void setnum(int num) { this.num = num; } } what is output after the executation of following code? mynumber obj1 = new mynumber(); mynumber obj2 = new mynumber(10); obj2 = obj1; obj2.setnum(20); system.out.println(obj1.getnum() “,” obj2.getnum());
given the following class: class mixer { mixer() { } mixer(mixer m) { m1 = m; } mixer m1; public static void main(string[] args) { mixer m2 = new mixer(); mixer m3 = new mixer(m2); m3.go(); mixer m4 = m3.m1; m4.go(); mixer m5 = m2.m1; m5.go(); } void go() { system.out.print("hi "); } } what is the result?
现有 public class parent{ public void change (int x){ } } public class child extends parent{ //覆盖父类change方法 } 下列哪个声明是正确的覆盖了父类的change方法?
class ca{ int num = 1; ca(int num){ this.num = num; system.out.print(this.num); } } class cb extends ca{ int num = 2; cb(int num) { this.num = num; system.out.print(num); } public static void main(string[] args) { ca a = new cb(5); } } 运行代码,程序输出结果为:
下面关于继承的叙述正确的是()
给定下列程序,请选出正确结果。 class cat { cat (int c) { system.out.print ("cat" c " "); } } class subcat extends cat { subcat (int c){ super (5); system.out.print ("cable"); } subcat() { this (4); } public static void main (string [] args) { subcat s= new subcat(); } }
下列程序的输出是()。 class other{ public other () { system.out.print("other!"); } } public class driver1 extends other { public static void main( string[] args ) { new driver1(); new other (); } }
请选出以下程序的输出结果 class a { public void func1() { system.out.println("a func1 is calling"); } public void func2() { func1(); } } class b extends a { public void func1() { system.out.println("b func1 is calling"); } public void func3() { system.out.println("b func3 is calling"); } } class c { public static void main(string[] args) { a a = new b(); a.func1(); a.func2(); a.func3(); } }
请选出以下程序的输出结果 public class child extends people { people father; public child(string name) { system.out.print(3); this.name = name; father = new people(name ":f"); } public child() { system.out.print(4); } public static void main(string[] args) { new child("alice"); } } class people { string name; public people() { system.out.print(1); } public people(string name) { system.out.print(2); this.name = name; } }
请选出正确答案 class parent { string one, two; public parent(string a, string b){ one = a; two = b; } public void print(){ system.out.println(one); } } public class child extends parent { public child(string a, string b){ super(a,b); } public void print(){ system.out.println(one " to " two); } public static void main(string arg[]){ parent p = new parent("south", "north"); parent t = new child("east", "west"); p.print(); t.print(); } }
请选择正确的输出结果 class guy { public guy(){ system.out.print("111,"); } } class cowboy extends guy { public cowboy(){ system.out.print("222,"); } } class wrangler extends cowboy { public wrangler(){ system.out.print("333,"); } } public class greeting2 { public static void main(string[] args) { guy g1 = new guy(); guy g2 = new cowboy(); guy g3 = new wrangler(); } }
给定以下程序 class pencil { public void write (string content){ system.out.println( "write" content); } } class rubberpencil extends pencil{ public void write (string content){ system.out.println("rubber write" content); } public void erase (string content){ system.out.println( "erase " content); } } 执行下列代码的结果是哪项? pencil p=new pencil(); (( rubberpencil) p).write("hello");
下面关于变量及其范围的陈述哪些是错误的
下列说法错误的是
以下代码 class finaltest{ int num = 1; public static void main(string[] args) { final finaltest ft = new finaltest();//1 ft.num = 100;//2 //3 system.out.println(ft.num);//4 } }
下列代码执行结果是 class numtest{ static int id = 1; int id2 = 1; numtest(int id,int id2){ this.id = id; this.id2 = id2; } void printid(){ system.out.print(id id2 " "); } public static void main(string[] args) { numtest a = new numtest(1,2); numtest b = new numtest(2,1); numtest c = new numtest(0,0); a.printid(); b.printid(); c.printid(); } }
以下代码 class finaltest{ final int num = 1; public static void main(string[] args) { final finaltest ft = new finaltest();//1 ft.num = 100;//2 //3 system.out.println(ft.num);//4 } }
class numtest{ final int id = 1; int id2 = 1; numtest(int id,int id2){ this.id = id; this.id2 = id2; } void printid(){ system.out.print(id id2 " "); } public static void main(string[] args) { numtest a = new numtest(1,2); numtest b = new numtest(2,1); numtest c = new numtest(0,0); a.printid(); b.printid(); c.printid(); } }
下列代码执行结果是 class numtest{ final static int num1 = 1; static int num2 = 1; void printnum1(){ system.out.print(num1 " "); } void printnum2(){ system.out.print(num2 " "); } public static void main(string[] args) { numtest a = new numtest(); a.num2 ; a.printnum1(); numtest b = new numtest(); b.printnum2(); } }
下列代码执行结果是 class numtest{ final static int num1 = 1; static int num2 = 1; void printnum1(){ system.out.print(num1 " "); } void printnum2(){ system.out.print(num2 " "); } public static void main(string[] args) { numtest a = new numtest(); a.num1 ; a.printnum2(); numtest b = new numtest(); b.printnum1(); } }
以下代码执行结果是 class statictest{ static{ system.out.print("a "); } static{ system.out.print("b "); } public static void main(string[] args) { statictest st1 = new childtest(); } } class childtest extends statictest{ static{ system.out.print("c "); } }
以下代码执行结果是 class statictest{ static{ system.out.print("a "); } { system.out.print("b "); } public static void main(string[] args) { statictest st2 = new childtest(); //main1 system.out.print(“ # ”); //main2 statictest st = new statictest(); //main3 } } class childtest extends statictest{ static{ system.out.print("c "); } }
有如下类定义: public class classandvariables{ public static int x = 8; public int y = 9; } 执行如下代码: classandvariables a = new classandvariables(); classandvariables b = new classandvariables(); a.y = 5; b.y = 6; a.x = 1; b.x = 2; 则a.y, b.y, a.x, b.x的值分别为:
请阅读以下程序,并写出结果 public class argumentpassing { public static void changevalue(int a) { a = 10; } public static void changevalue(string s1){ s1 = "def"; } public static void changevalue(stringbuffer s1) { s1.append("def"); } public static void main(string[] args) { int a = 5; string b = "abc"; stringbuffer c = new stringbuffer("abc"); changevalue(a); changevalue(b); changevalue(c); system.out.print(a); system.out.print(b); system.out.print(c); } }
下列关于构造方法的叙述中,错误的是
关于以下程序段,正确的说法是()。 string s1= "abc" "def"; //1 string s2= new string(s1); //2 if (s1==s2) //3 system.out.println("= = succeeded"); //4 if (s1.equals(s2)) //5 system.out.println(".equals() succeeded"); //6
请阅读以下程序,并写成结果。 class father { public void hello() { system.out.println("father says hello."); } } public class child extends father { public void hello() { system.out.println("child says hello"); } public static void main(string[] a) { child foo = new child(); //foo.hello(); father foo2 = (father) foo; //foo2.hello(); child foo3 = (child) foo2; //foo3.hello(); system.out.println(foo==foo2); system.out.println(foo==foo3); } }
运行如下程序,输出结果是()。 stringbuffer = new stringbuffer("good morning!"); string sub = .substring(0, 8); system.out.println(sub); system.out.print("/"); char c = .charat(6); system.out.println(c);
如下所示的test类的java程序中,共有几个构造方法()。 public class test{ private int x; public test(){} public void test(int i){ this.x=i; } public test(string str){}}
下面代码的运行结果为:() public class foo { static string s; public static void main (string[]args) { system.out.println ("s=" s); } }
已知如下代码:( ) public class test { public static void main(string arg[] ) { int i = 5; do{ system.out.print(i); }while(-i>5); system.out.print("finished"); } } 执行后的输出是什么?
given: abstract class bar { public int getnum() { return 38; } } public abstract class abstracttest { public int getnum() { return 45; } public static void main(string[] args) { abstracttest t = new abstracttest() { public int getnum() { return 22; } }; bar f = new bar() { public int getnum() { return 57; } }; system.out.println(f.getnum() " " t.getnum()); } } what is the result?
public class child extends people { people father; public child(string name) { system.out.print(3); this.name = name; father = new people(name ":f"); } public child() { system.out.print(4); } public static void main(string[] args) { new child("alice"); } } class people { string name; public people() { system.out.print(1); } public people(string name) { system.out.print(2); this.name = name; } }
现有: class guy{ string greet(){ return "hi "; }} class cowboy extends guy{ string greet(){ return "howdy "; }} class wrangler extends cowboy{ string greet(){ return "ouch! "; } } class greetings2 { public static void main (string [] args) { guy g=new wrangler(); guy g2=new cowboy(); wrangler w2=new wrangler(); system.out.print(g.greet() g2.greet() w2.greet()); } } 结果是什么?
现有: class tree { private static string tree = "tree"; string gettree() { return tree; } } public class elm extends tree { private static string tree = "elm"; public static void main(string[] args) { new elm().go(new tree()); } void go(tree t) { string s = t.gettree() elm.tree tree (new elm().gettree()); system.out.println(s); } }
接口是java面向对象的实现机制之一,以下说确的是:( )
如果想要一个类不能被任何类继承的话,需要使用哪个关键字来修饰该类?
class person { private int a; public int change(int m){ return m; } } public class teacher extends person { public int b; public static void main(string arg[]){ person p = new person(); teacher t = new teacher(); int i; // point x } } which are syntactically valid statement at // point x?
请问以下代码的输出是什么: class a { public static int x = 10; public static void printx() { system.out.print(x); } } public class elm extends a { public int x = 20; public static void main(string[] args) { a a = new elm(); printx(); system.out.print("和"); system.out.print(a.x); } }
类 teacher 和 student 是类 person 的子类; teacher t; student s; // t and s are all non-null. if (t instanceof person ){ s=(student)t; } 最后一条语句的结果是:
下述代码的执行结果是 class super { public int getlength() { return 4; } } public class child extends super { public long getlength() { return 5; } public static void main(string[] args) { super sooper = new super(); super sub = new child(); system.out.print(sooper.getlength() "," sub.getlength()); } }
下列关于interface的说确的是:
验证身份证号码是否正确
验证身份证号码是否正确(带校验算法)
给出如下代码段: try { int x = integer.parseint("two"); } 下列哪个可以作为catch的异常?
给出下列代码: class plane { static string s = "-"; public static void main(string[] args){ new plane().s1(); system.out.println(s); } void s1() { try {s2();}catch (exception e){ s = "c"; } } void s2() throws exception { s3(); s = "2"; s3(); s = "2b"; } void s3() throws exception{ throw new exception(); } } 结果是什么?
下列程序的执行,说确的是( ) class multicatch { public static void main(string args[]) { try { int a=args.length; int b=42/a; int c[]={1}; c[42]=99; //10行 system.out.println(“b=” b); } catch(arithmeticexception e) { system.out.println(“除0异常:” e); //15行 } catch(arrayindexoutofboundsexception e) { system.out.println(“数组超越边界异常:” e); //19行 } } }
下面是一些异常类的层次关系: java.lang.exception java.lang.runtimeexception java.lang.indexoutofboundsexception java.lang.arrayindexoutofboundsexception java.lang.stringindexoutofboundsexception 假设有一个方法x,能够抛出两个异常,array index和string index异常,假定方法x中没有try-catch语句处理这些异常,下面哪个答案是正确的?( )
请问所有的异常(exception)和错误(error)类皆继承哪一个类?( )
pubic void test () { try { onemethod (); system.out.print ( "condition 1"); } catch ( exception e ) { system.out.print ( "condition 3"); } catch ( arithmeticexception e ) { system.out.print ( "condition 2" ); } finally { system.out.println ("condition 4" ); } } which will display if onemethod throw nullpointerexception?
given: import java.io.*; class master { string dofilestuff() throws filenotfoundexception { return "a"; } } class slave extends master { public static void main(string[] args){ string s = null; try { s = new slave().dofilestuff();}catch ( exception x){ s = "b"; } system.out.println(s); } // insert code here } which, inserted independently at // insert code here, will compile, and produce the output b? (choose all that apply.)
given import java.io.*; class main{ public void f1() throws arithmeticexception{} public void f2() throws filenotfoundexception{} public static void main(){ new main().f1(); //line1 new main().f2(); //line2 } } which is correct?
class emu{ static string s = "-"; public static void main(string[] args){ try{ throw new exception(); }catch(exception e){ try{ try{ throw new exception(); }catch (exception ex){ s = "ic "; } throw new exception(); } catch(exception x){ s = "mc "; } finally{ s = "mf "; } }finally{ s = "of "; } system.out.println(s); } } what is the result?
given: class mineral{ } class gem extends mineral{ } class miner{ static int x = 7; static string s = null; public static void getweight(mineral m){ int y = 0 / x; system.out.print(s " "); } public static void main(string[] args){ mineral[] ma = {new mineral(), new gem()}; for(object o : ma) getweight((mineral) o); } } and the command-line invocation: java miner what is the result?
请完成汇率和金额排序程序。
谈谈新冠疫情改变了你的哪些生活方式。
计算机网络是分布在不同地理位置的多个独立的( ) 的。
分布式计算机系统与计算机网络系统的重要区别是( )。
计算机网络是计算机技术和通信技术相结合的产物这种结合开始于( )。
21世纪是一个以网络为核心的信息时代。这里所说的网络是计算机网络。( )
计算机网络是指将地理位置不同的具有独立功能的多台计算机及其外部设备,通过通信设备和线路连接起来,实现资源共享和信息传递的计算机互联系统。 ( )
计算机网络的主要功能有: ( )、数据传输和进行分布处理。
计算机网络中可以共享的资源包括( )
计算机网络最基本的功能是: ( )
计算机网络拥有可靠性、高效性、独立性、扩充性、廉价性、分布性、易操作性的特点( )
在网络设备中,传输数据信号的物理通道,可将各种设备相互连接起来的是( )
从功能上来说,计算机网络是由硬件和软件两大部分构成的;从系统组成上来讲,计算机网络分为通信子网和资源子网两部分。
网络硬件一般包括网络操作系统、网络协议软件、网络管理软件、网络通信软件、网络应用软件五部分组成
网络通信软件是用于实现网络中各种设备之间进行通信的软件
计算机网络硬件是由计算机、通信处理机、传输介质和_____等构成。
在哪个范围内的计算机网络可称之为局域网( )
下列不属于广域网的是
在计算机网络中一般局域网的数据传输速率要比广域网的数据传输速率
计算机网络按网络覆盖范围分,可分为个人区域网pan、局域网lan、城域网man、广域网wan和互联网internet。
局域网一般都是专用网,通常都是为某个单位所拥有,非本单位的人一般都无法使用本单位安装的局域网。
星形拓扑结构适用于( )
计算机网络的拓扑结构是指 ( )。
下列属于星形拓扑的优点的是( )
星型拓扑结构是以结点为中心,把若干外围结点连接起来的幅射式的互连结构。
蜂窝结构的特点是网络建设时间长,且不易于扩展。
一般而言,信号可以分成哪两类( )
常用的数据传输速率单位有kbps、mbps、gbps,1gbps等于( )
描述计算机网络中数据通信的基本技术参数是数据传输速率与( )
吞吐量受网络带宽或网络额定速率的限制
按介质的不同,通信可分为两大类:一类称为有线通信,另一类称为无线通信。
波特率和比特率几乎没有什么区别
宽带传输适用于远距离的广域网和互连网的主干线的数据传输。
1.如要进行语音信息的传输,声音的带宽为4000hz,定义采用频率为该声音带宽的两倍为8000次/s,用8位二进制编码,则为保证该语音信息能够被快速传递的信道的数据传输速率最低为: kbps。
多路复用技术的主要目的不包括( )
下列关于信道容量的叙述,正确的是( )
信道共享技术包括静态复用和动态接入两类。
时分复用中频带的信道按时间划分成等长的时分复用帧。
频分复用在整个通信过程中用户始终占用着这个频带。
按照信号传送方向与时间的关系,信号在传输上存在哪几种方式( )
下列哪种是全双工传输模式( )
电话网使用下列哪种交换方式( )
在数据传输中, ( )的传输延迟自小
数据传输中,需要建立连接的是( )
采用交换技术的计算机通信网络的核心设备不是路由器
报文交换不能进行不同速率、不同码型的交换,以保证传输内容的同一性
下列关于双绞线错误的是
光缆和铜线相比下
铜线、光缆和电力线中光缆是一种更为普遍的导线
一根双绞线由五部分组成,主要包括外套、外屏蔽、内屏蔽、绝缘和_____。
光导纤维是一种直径很细的、很柔软、能传导_____的介质。
以下微波特点正确的是
下列说确的是
整个赤道上空能放置无数颗同步卫星
无线电波的传播方式有直线传播和_____两种。
激光通信是一种利用_____传输信息的通信方式
计算机网络中,分层方法和协议的称为计算机网络的 ( )
2.相互通信的两个计算机系统必须高度协调,而这种“协调”是相当复杂的,因为计算机网络要解决各种复杂的技术问题
程序设计中对复杂问题进行模块化处理,而计算机网络中则将该复杂系统进行______,每层完成特定功能,各层协调一致实现整个网络系统。
网络协议组成部分为( )。
一组用来决定数据的格式与传输过程的规程被称为( )。
网络通信协议的三大要素是语法、语义、同步
计算机网络体系结构包括协议和接口两个部分
在osi七层结构模型中,处于数据链路层与传输层之间的是 ( )
完成路径选择功能是在osi模型的 ( )
在osi中,为网络用户间的通信提供专用程序的是 ( )
数据分组在osi的( )被封装成数据帧。
在osi的( )描述了各种不同的网络介质。
osi参考模型从底层向上分为:物理层、数据链路层、网络层、传输层、表示层、会话层、应用层7各层次
osi模型是一个应用模
在tcp/ip体系结构中,udp协议工作在 ( )
在tcp/ip体系结构中,tcp协议工作在 ( )
关于tcp/ip协议的描述中,下列哪个是错误的?
ftp与http位于tcp/ip的( )。
tcp/ip的层次结构中应用层包括osi模型的传输层、表示层、应用层三层。( )
tcp/ip的网络接口层是网络访问层,其主要功能是负责与物理网络的连接。( )
1.以下网卡依据传输带宽来区分错误的是
2.下列不是常见的网卡分类方式的是
3.网卡可以接受和发送数据,并将其转换成所需要的格式
4.网卡是网络接口卡的简称,又称为_____是一种外设卡
以下关于集线器的介绍错误的是
集线器采用下列哪些方式进行分类
中继器是局域网环境下用来延长网络距离的最简单最廉价的网络互联设备
集线器俗称hub,是一种特殊的多端口_____
利用集线器可以组建成_____或者_____拓扑结构的共享式网络
下列关于交换机的介绍错误的是
交换机和集线器的区别主要体现在
按交换机的大小可将交换机分为企业级交换机、部门级交换机和工作组交换机等
目前常见的交换机帧转发方式有 直接交换、改进的直接交换和_____三种
关于路由器的介绍错误的是
关于路由器的分类及区别下列错误的是
路由器是用于连接多个运行不同协议的局域网,也就是用于异种网络互连的网络连接设备
互联网中只有在高级别的网络中可见到路由器
路由器的工作包括两个过程,一是_____,二是转发。
下列哪些属于一个电子产品设计的基本环节。
功能与技术指标是电子产品设计的出发点,整个电子产品设计要满足功能与技术指标
软件编程完成后,就可以直接烧录到电子产品中使用。
关于系统的基本组成中,下列哪一个组成部分是整个电子产品的核心部分,控制着整个电子系统
关于系统的基本组成中,下列哪一个组成部分是电子产品感知外部条件和环境的主要组件?
摄像头一般也是一种传感器,感知图像。
哪一个传感器可感知光线亮度?
传感器接入单片机处理器时,要根据传感器的输出是模拟还是数字,选择是否需要ad采集。
下列哪一种无线通信功耗最低
常见的无线通信有
选择无线通信时,不仅要考虑功耗,传输距离外,还要考虑到收发双方的可用性。
下列关于元器件的选型原则,哪些是正确的。
下列关于元器件选择,正确的是:
一个典型的通信电子产品设计时应该包含哪些部分?() a. 微处理器 b. 电源 c. 通信模块 d. 传感器及通信模块
关于通信电子产品的方案设计,哪些说法是正确的? a. 单片机不需要晶振也可以工作 b. 电源的设计最好是核心元器件确定下来后再选择 c. 设计单元电路时,尽量选择集成电路 d. 传感器的输出如果是数字输出,则可以直接与单片机引脚相连
所有的数字电路之间可以直接连接
选择adc模块时,只有当adc的采样频率满足_______条件时,才能对模块信号进行采集
晶振周期与机器周期的关系_______
提交温湿度远程监控的系统设计,要求: (1)画出系统框图。 (2)针对系统的每一部分,提出至少2两种方案,包括元器件信号,参数。并比较方案的优缺点。 (3)画出元器件的电路草图
提交温湿度远程监控的系统设计,要求: (1)画出系统框图。 (2)针对系统的每一部分,提出至少2两种方案,包括元器件信号,参数。并比较方案的优缺点。 (3)画出元器件的电路草图
建立原理图文件后,不可以修改原理图纸的大小。
通过点击原理图图纸______的方块,可以直接打开图纸设置界面,可以对原理图纸进行设置。
可以通过菜单栏的design下的___________添加响应的原理图库、pcb库及集成库。
在绘制原理图时,可以使用快捷键绘制图形,可以连续依次点击_______和________字幕键放置线。
绘制原理图库的时候,通常将元器件绘制在图形的()
一个自定义原理图库文件只能放置一个元器件
绘制原理图库时,将引脚的有“x”的一侧朝外。
自定义原理图库可以通过菜单栏中的__________新建。
原理图库文件的后缀名为_________。
通过鼠标_______引脚,可以打开引脚的属性界面,以便更改引脚的属性。
下列哪些属于ad中引脚的电气类型(electrical type)
7805三端ic 的含义分别是 ______、_______和_______。
78** 系列的稳压集成块的极限输入电压是_____v
lm1117 电压范围
下列关于lcd1602的技术参数,哪些是正确的。
lcd1602中的rw引脚为高电平时,表示向lcd写入指令与数据
lcd1602显示屏是
lcd1602显示容量是共能输出_____列_____行的字符。
lcd1602采用标准的_______个引脚接口。
usr-c215功能
usr-c215引脚是____插针封装
具有相同网络标号的线,连接在一起,一个原理图中相同的网络标号只可能有两个
text与netlabel的功能相同
下图原理图表示的三极管类型为npn。
当按键使用比较少时,可使用______按键设计按键电路
拉低c215的nreload超过______秒以上,该模块就会恢复出厂配置
下列哪一个不属于按照电容材料分类而来的电容
下列哪一个不是电容的主要功能
为了经精确表示串口波特率,一般51单片机晶振可以设置为:
altimum designer自带的库文件无法编辑与复制
ad绘制原理图时,不同元器件之间必须通过走线才能完成连接。
原理图库文件修改成功后,已经绘制好的原理图会自动更新
元器件的引脚属性比如标号,可以直接在原理图中修改,并不一定要在库中修改。
s9014是pnp三极管
不同元器件的注释可以相同
如果原理图元器件太多,而放置不下时,可以修改原理图的页面属性,调整页面大小。
led电路根据led的正还是负极连接到单片机上,可以设计成______种电路。
usr-c215的rx引脚须经过ttl转换电路连接到51单片机的_____引脚
鼠标左键按住元器件,然后点击_______键,可以直接打开元器件的属性窗口。
关于pcb的层的概念,用于定义pcb板框的是( )层
pcb层中,用于标记顶部丝印,如标注pcb元器件标记的层为( )
关于pcb走线的宽度,所有走线的宽度必须相同
pcb绘制中,可以通过设置坐标原点设置绘制边框大小,可以通过菜单栏_____________设置(英文)
1密耳 = _______毫米
下列哪些封装是51单片机所使用的封装( )
51单片机中引脚的序号必须与其封装的引脚号一致
原理图的引脚在pcb封装中,一般是用焊盘绘制。
pcb绘制界面左上角坐标表示_____.
可以通过___________快速新建一个dip pcb封装
测量焊盘之间的距离快捷键是____.
一般过孔的直径一般不小于________mm
一般过孔直径要至少大于引脚直径________mm。
对于直径大于2mm的过孔,其焊盘直径至少为过孔直径的_______倍
对于直径小于0.4mm的过孔,其焊盘直径一般为过孔直径的_______倍
绘制完成的pcb元器件封装图将会放在______文件里
栅格是_____ 即鼠标动一下的最小移动距离
修改元器件的名称要在______中完成。
lcd1602 字符尺寸 ____
下列哪些属于pcb布局的一般原则( )
电源电路应该尽量的布在板子边缘。
0.1uf 去耦电容应该尽量靠近电源布局。
布线时,通常信号线的宽度 > 地线宽度 > 电源线宽度
走线拐弯时,可以直接画成直角。
标注元器件的方法是在菜单栏_____.
原理图的导入在菜单栏design 下的______可以完成。
删除room区域可以按____键完成
ad布线有_______、_________两种方法。
pcb中旋转元器件的快捷键是( )
下列关于pcb布局的说法错误的是:
下列关于pcb布线,说法错误的是( )
下列关于pcb库的说法,错误的是()
mechanical层要比keepout层小。
topoverllayer层在toplayer层的上面。
过孔是横穿整个pcb层的一个物理结构
一般焊盘直径要比引脚直径大0.2~0.3mm
1. 写出温湿度远程监控pcb板的一般步骤?并将pcb绘制文件、pcb库文件以附件形式上传到作业文件。
写出在使用altium designer绘制原理图与pcb遇见哪些问题?如何解决的?
杜邦线分为____,______,______,
杜邦线的功能是__________。
用万用表调试硬件pcb时,要断电检测通路,通电检查电压
静态pcb调试的主要目的是查看程序的运行情况。
在uvsion工程文件里,新建一个文件,该文件就已经添加到工程文件里。
可以通过工具栏的manage components 工具栏添加已经有的文件。
lcd1602显示2行________列的字符
12mhz晶振下,定时器0采用工作方式1,则如果定时时间在1ms,则th0的值为()
默认方式下,51单片机的定时器1的优先级是()
控制串口发送工作方式的51单片机的寄存器是( )
usr-c215默认的ip地址是()
51单片机中,控制波特率加倍的寄存器是pcon的最高位
12mhz晶振的51单片机,波特率设置是完全精确的。
51单片机的工作方式1是一种11bit的异步通信方式
51单片机串口发送的波特率由定时器0提供
51单片机定时器的工作方式2是8位自动重载模式。
中断服务子程序在函数名后,需要添加的一个关键字为:
定时器中断0对应的优先级为()
51单片机中,控制串口接收使能的是scon中的()位
下列定时器工作方式中,哪个工作方式是16bit定时器。
pcon中,波特率加倍bit位,处在第_____位(从0位开始算)
下列关于中断的说法,正确的是()
非中断模式下,定时器的标志位tf0/tf1不需要手动复位
串口的工作方式中,工作方式0是固定波特率
串口的工作方式中,工作方式1是固定波特率
串口的工作方式中,工作方式2是11bit 串口通信方式
51单片机的串口通信是一种异步通信方式
dht11是一种单线通信方式
中断服务子程序可以被函数调用
lcd1602,在不同晶振频率下,驱动程序完全一样。
part i: choose from the following groups of words the one you hear. each of the words will be read once only.
choose from the following groups of words the one you hear. each of the words will be read once only.
choose from the following groups of words the one you hear. each of the words will be read once only.
choose from the following groups of words the one you hear. each of the words will be read once only.
choose from the following groups of words the one you hear. each of the words will be read once only.
choose from the following groups of words the one you hear. each of the words will be read once only.
choose from the following groups of words the one you hear. each of the words will be read once only.
choose from the following groups of words the one you hear. each of the words will be read once only.
choose from the following groups of words the one you hear. each of the words will be read once only.
choose from the following groups of words the one you hear. each of the words will be read once only.
part ii: the following pairs of sentences are exactly the same except for one word. you will hear either sentence (a) or (b). choose the one you hear.
the following pairs of sentences are exactly the same except for one word. you will hear either sentence (a) or (b). choose the one you hear.
the following pairs of sentences are exactly the same except for one word. you will hear either sentence (a) or (b). choose the one you hear.
the following pairs of sentences are exactly the same except for one word. you will hear either sentence (a) or (b). choose the one you hear.
the following pairs of sentences are exactly the same except for one word. you will hear either sentence (a) or (b). choose the one you hear.
the following pairs of sentences are exactly the same except for one word. you will hear either sentence (a) or (b). choose the one you hear.
the following pairs of sentences are exactly the same except for one word. you will hear either sentence (a) or (b). choose the one you hear.
the following pairs of sentences are exactly the same except for one word. you will hear either sentence (a) or (b). choose the one you hear.
the following pairs of sentences are exactly the same except for one word. you will hear either sentence (a) or (b). choose the one you hear.
the following pairs of sentences are exactly the same except for one word. you will hear either sentence (a) or (b). choose the one you hear.
part iii: the following pairs of sentences are exactly the same, except a different word is stressed (stronger) in each sentence. choose the sentences you hear in each group.
the following pairs of sentences are exactly the same, except a different word is stressed (stronger) in each sentence. choose the sentences you hear in each group.
the following pairs of sentences are exactly the same, except a different word is stressed (stronger) in each sentence. choose the sentences you hear in each group.
the following pairs of sentences are exactly the same, except a different word is stressed (stronger) in each sentence. choose the sentences you hear in each group.
the following pairs of sentences are exactly the same, except a different word is stressed (stronger) in each sentence. choose the sentences you hear in each group.
part iv: listening comprehension: in this section, you are going to listen to hear 10 sentences. please listen carefully and decide which of the sentences in the three choices is closest in meaning to the one you hear.
in this section, you are going to listen to hear 10 sentences. please listen carefully and decide which of the sentences in the three choices is closest in meaning to the one you hear.
in this section, you are going to listen to hear 10 sentences. please listen carefully and decide which of the sentences in the three choices is closest in meaning to the one you hear.
in this section, you are going to listen to hear 10 sentences. please listen carefully and decide which of the sentences in the three choices is closest in meaning to the one you hear.
in this section, you are going to listen to hear 10 sentences. please listen carefully and decide which of the sentences in the three choices is closest in meaning to the one you hear.
in this section, you are going to listen to hear 10 sentences. please listen carefully and decide which of the sentences in the three choices is closest in meaning to the one you hear.
in this section, you are going to listen to hear 10 sentences. please listen carefully and decide which of the sentences in the three choices is closest in meaning to the one you hear.
in this section, you are going to listen to hear 10 sentences. please listen carefully and decide which of the sentences in the three choices is closest in meaning to the one you hear.
in this section, you are going to listen to hear 10 sentences. please listen carefully and decide which of the sentences in the three choices is closest in meaning to the one you hear.
in this section, you are going to listen to hear 10 sentences. please listen carefully and decide which of the sentences in the three choices is closest in meaning to the one you hear.
part ii. passage (shadowing and gist) directions: listen to the passage and choose the best answer to each of the following questions. what does the speaker really describe in the speech?
irections: listen to the passage and choose the best answer to each of the following questions. how do specialists comment on this study method?
directions: listen to the passage and choose the best answer to each of the following questions. how effectively can the average person learn during sleep as in the same period during the day?
directions: listen to the passage and choose the best answer to each of the following questions. what does sleep-teaching do?
directions: listen to the passage and choose the best answer to each of the following questions. what did the student have to do for another three hours before having breakfast?
part iii. news (shadowing and gist) a. directions: listen to the news item and complete the following summary. this news item is about .
directions: listen to the news item and choose the best answer to complete the following sentences. opposition parties are demanding after a violent protest over voting problems tuesday.
there were at least killed and injured during the voting.
people at more than 100 voting places .
show the ruling general people’s congress party in the lead.
part i (note-taking) directions: listen to a talk about light and health. take notes and complete the following summary. can light affect your health? many researchers believe that light can affect both your physical and your (1) .
from daylight, our bodies absorb vitamin d through the skin. certain skin diseases also (2) from exposure to sunlight.
light absorbed through the eye can stimulate hormone production, which in turn (3) our mood.
some people become (4) in winter, when the days are dark and most people spend less time in the open air.
when spring comes, these (5) disappear. researchers have called this condition sad -- seasonal affective depression.
the condition can be (6) by exposing patients to special lights, known as full-spectrum lights.
this lighting has also been used to treat patients (7) from jet-lag, to improve learning in school-children in russia and america,
and the (8) of japanese factory workers
young people need at least fifteen minutes a day in real daylight in summer (9) in winter.
old people, who risk vitamin d deficiency, should spend even longer exposed to (10) daylight.
corporate culture corporate culture is described as the (1) _____________ of an organization, and guides how employees think, act, and feel.
it includes core values and beliefs, corporate ethics, and rules of behavior. it can be expressed in the company’s mission (2) _____________ and other communications,
in the architectural style or interior (3) _____________ of offices, and in the titles given to various employees. corporate culture affects you in many ways.
for instance: l the (4) __________ __________ per day, per week.
the (5) __________ __________, including employee interaction, competition degree, etc.
the (6) __________ __________, including the accepted styles of attire, etc.
the (7) __________ __________ you get, including cubicles, window offices, etc.
the (8) __________ __________ development.
onsite perks, such as break room, play room, etc. l the (9) __________ __________ outside the office.
(10) _____________ with other employers.
peak performances - moments when children (1) that's in them -
are the stuff of every parent's (2) .
and yet most of us have seen a report card or heard a trumpet solo that (3)
what our kids can (4) .
why can some boys and girls repeatedly pull themselves to the (5)
while others of equal or (6) cannot?
many parents assume skill is pretty much determined by (7)
the student with the highest i.q. will get the best grades, or the athlete with the most prowess will (8) .
genes (9) in determining performance, but they're not everything.
the edge comes from mental attitude, character and (10) .
there are some simple ways for parents to help their youngsters develop those (11)
find something to praise. a child who feels good about himself (12)
assess your child's (13)
encourage self-applause. knowing how to relax is key to (14) .
a good report card (15) near your daughter's mirror reminds
her that she can do well and (16) to repeat her success.
there are no (17) to bringing your child to do his best.
it's a (18) of support, encouragement and hard work.
and those efforts (19) not only in peak performance
not only in peak performance but also in (20) between parent and child.
news item from voa, bbc and cri part i directions: listen to the news item and complete the following passage. creating a classroom environment that treats women and men equally is important for the educational success of students. however ____1______ equality does not stop with the teacher.
it is also important that the ____2______ used are supporting _____3_____ treatment.
in fact, many classroom materials, especially those that are older, may contain gender bias in _____4_____, photos, or words.
these materials can include textbooks, _____5_____, reading materials, written assignments, or even test materials.
having students use materials like these in class can reinforce _____6_____ about gender roles in society.
classroom materials that reinforce gender stereotypes can ____7______ students,
weaken their motivation and limit their overall _____8_____ performance.
this can result in fewer opportunities available to students when they finish their schooling. research has found that stereotypes and gender bias in english language materials do _____9_____.
several studies by the united nations educational, scientific, and cultural organization, or unesco, have found that some texts ____10______ women, contain stereotypes about women or offensive comments about women.
in addition, research has found that _____11_____ in teaching materials
often show a male _____12_____.
one study on high school english language textbooks in iran found that male characterizations were used as much as _____13_____ of the time.
one study on high school english language textbooks in iran found that male characterizations were used as much as _____13_____ % of the time.(请填写数字)
the first step is to understand how to identify gender bias in textbooks. examine the image below. these images were taken from an english language textbook. what do you notice about how the men and women are being _____14_____?
in this image there are six people, four men and two women, shown in different jobs. the men pictured include a construction worker, a doctor, a police officer, and a truck driver. the women shown include a farm worker and a food store employee. this image shows men and women in _____15____ jobs in two ways.
first, male representation is double that of female. second, the men generally are working in higher-level, more economically powerful jobs. now look at a short reading activity from an actual english language textbook. what do you notice about the ________ of men and women in the example?
part ii directions: listen to the news item and complete the following passage. a new report says about ___1__ people
a day have been forced to __2__ their homes in african conflict
and __3__ zones.
figures show that more than __4__ people in africa are internally displaced. (请填文字)
nearly __5___left their homes last year.(请填文字)
part iii directions: listen to the news item and complete the following passage. britain's most prestigious ___1___art award,
the turner prize have been won by an art professor who was born in zanzibar, lubaina himid. judges __2___ her work
which explored the african diaspora and black ___3__.
professor himid is the first black woman and the oldest person to win the__4__.
part i listening to a song directions: listen and fill in the blanks with the missing information. although (1) __________ has always been a friend of mine.
i'm leaving my life in your (2) __________.
people say i'm (3) __________
and that i am (4) __________.
risking it (5) __________ in a glance.
how you got me blind is still a (6) __________.
i can't get you out of my (7) __________
don't care what is written in your (8) __________.
as long as you're (9) __________ with me. i don't care who you are. where you're from. what you did.
why did mr. power ask mr. hanson to call later?
why should the report be photocopied in the morning?
why was mr. power especially displeased about miss davis’s call to her boyfriend?
what do you think of miss wright?
what can you learn from the dialogue?
(dialogue 2:6-10)why has laura come to the office?
who is miss davis?
when do people in the finance section start work?
what do you know about linda?
why does linda feel a little nervous today?
(dialogue 3:11-15) why did the woman come to complain to the manager?
what excuse did the manager make for the problems?
what did the manager promise to do?
what do you know abut the hotel?
what does the dialogue mainly tell us?
part ii passages directions: you're going to hear three short passages. each will be read twice. at the end of each passage, you will hear some questions. choose the best answer to each question. (2 points for each) passage 1 which of the following is true according to the passage?
which of the following would be the best title for the passage?
passage 2 (18-20)why did the artly dressed man come to the jewelry shop one day?
which of the following was of no importance to the man?
what did the old lady take to the jewelry shop?
how much did the shop lose in the deal?
passage 3 (22-25) which of the following is not necessary for a young man who wants to drive alone?
what must a person do in the driving test?
which of the following is mentioned in the passage?
what is this passage mainly about?
please translate the following chinese sentence into english. pay attention to the words in red. 平高度评价拉贝先生,认为他“对生命有大爱、对和平有追求”。
please translate the following english sentence into chinese. pay attention to the word in red. we will die before we give in.
please translate the following english sentence into chinese. consider the connotations and tones when doing translation. but there is good news for these thousands of sufferers: treatment options—old, new and still being researched—are available.
please translate the following english sentence into chinese. consider the connotations and tones when doing translation. when you educate a woman, the benefits cascade across society.
please translate the following english sentence into chinese: the sun rose thinly from the sea.
please translate the following english sentence into chinese: brown ducks flew across the water and landed in a nice skim on the moat.
please translate the following english sentence into chinese. pay attention to the word in red. the judge sat in his dining room amid his morning mail.
please translate the english sentence into chinese. pay attention to the word in red. at last, he whispered a hurried good bye to his host and darted toward the door.
please translate the chinese sentence into english. pay attention to the word in red. 梁武帝于大同年间命令住在长干寺旁的数百户人家献出宅地,用于扩建寺庙。
please translate the english sentence into chinese. pay attention to the words in red. the fight between the man and the fish became a tedious, tiring tug of war, compounded by rising temperatures. the excitement of the hook-up had long since been replaced by exhaustion. one hour passed, then two.
please translate the chinese sentence into english. 我在公园看见了迎春花,知道春天快要到了。
please translate the chinese sentence into english. 幸福家庭也有幸福家庭的烦恼。
please translate the following into chinese. pay attention to the meaning of the word "great." these are trees of great age.
please translate the following into chinese. pay attention to the meaning of the word "great." he is a great scoundrel.
please translate the following into chinese. pay attention to the meaning of the word "great." we had a great time at the party.
please translate the following into chinese. express the meaning of the word "fluid" appropriately. china is watching the fluid situation with concern in the middle east.
please translate the following into english. [hint: you may need to change the word order.] colds and flu are usually caused by viruses, so antibiotics - which work only on bacterial infections - won't help.
please translate the following into english. pay attention to the meaning of "年轻化". 目的是要使领导干部年轻化。
please translate the following into english. pay attention to tone of the sentence. 由于双方的共同努力,合同执行得非常顺利。
please translate the following into english. [hint: you may need to change the word order.] 医生为救病人,尽到了一切必要的努力。
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