nonylphenol is a kind of widely used non-ionic surfactant. what are the properties of its degradation products?
in 1948, the swiss chemist müller won the nobel prize in physiology or medicine for inventing and synthesizing which pesticide. however, after that, the large-scale application of the pesticide has caused a heavy burden on the ecological environment?
which of the statement about the toxicity of mercury in the environment is correct?
a non-rhotic speaker will pronounce words like far as /fɑːr/, whereas a rhotic speaker does not pronounce [r] at all unless followed by a vowel.
what is the name of the abbey?
关于织物组织表述正确的是( )
织造当经密比较大的织物,采用的穿综方法( )
按照产品的用途,纺织品设计可分为( )
there are two types of -ing noun combinations. for one type, the -ing form serves as a modifier of the noun and expresses the purpose of the noun; for instance, dining-room means the room for dining. in such circumstances, the word stress always falls on the ___________ element.
some words in english are shown in dictionaries as having three levels of stress: primary, secondary, unstressed or weak.
some words have little meaning of their own. their meaning can be inferred from certain context. such words are usually not accented even though they are the last content words.