英文请翻译一下啊啊啊..Mass spectrometry and chromatography are widely used instrumental techniques in chemistry.问题是,What are the main principles on which each of these techniques is based.这里的each是要回答Mass spectrometry还是 chromatography还是随便选1个?

问题描述:

英文请翻译一下啊啊啊..
Mass spectrometry and chromatography are widely used instrumental techniques in chemistry.
问题是,
What are the main principles on which each of these techniques is based.
这里的each是要回答Mass spectrometry还是 chromatography还是随便选1个?

两个都要呀~~~each is like each one, and 1+1=2...
o.O

我觉得是MS和chromatography都要
但是句子挺奇怪的,要么是把are去掉,要么是变成 Mass spectrometry and chromatography are widely used IN instrumental techniques in chemistry.

1.不是共同点,也不是选一个.
是每个都要解释.
其实问题就是:
Mass spectrometry is based on what principle
Chromatography is based on what principle
2.回jessica,这句话没问题.

质谱和色谱是在化学中被广泛应用的实验技术.
问题:
这些技术所依据的主要理论基础是什么.
不是两个中的一个,而是问这两种方法的共同点