求教doing的用法，OG12-SC-107

meeeelissa

[size=1em]Originally developed for detecting air pollutants, a technique called proton-induced X-ray [size=1em]　　emission, which can quickly analyze the chemical elements in almost any substance without [size=1em]　　destroying it, is finding uses in medicine, archaeology, and criminology. [size=1em]　　(A) Originally developed for detecting air pollutants, a technique called proton-induced X-ray emission, which can quickly analyze the chemical elements in almost any substance without destroying it, [size=1em]　　(B) Originally developed for detecting air pollutants, having the ability to analyze the chemical elements in almost any substance without destroying it, a technique called proton-induced X-ray emission [size=1em]　　(C) A technique originally developed for detecting air pollutants, called proton-induced X-ray emission, which can quickly analyze the chemical elements in almost any substance without destroying it, [size=1em]　　(D) A technique originally developed for detecting air pollutants, called proton-induced X-ray emission, which has the ability to analyze the chemical elements in almost any substance quickly and without destroying it, [size=1em]　　(E) A technique that was originally developed for detecting air pollutants and has the ability to analyze the chemical elements in almost any substance quickly and without destroying the substance, called proton-induced X-ray emission, 答案选A，CDE比较清楚，B选项说having是修饰前一个修饰语的，不太理解。“，doing”不是应该作为副词性修饰语修饰主句的吗？

vi.len

prep08：当现在/过去分词在句中且前后都有逗号,有歧义:1)修饰前面紧邻的名词,2)向后修饰后面句子的主语.
这种结构在GMAT肯定错,如果修饰某句主语,则避免将该分词置于以名词结尾的句后.避免方式:1)用定语从句/介词短语明确修饰对象.2)可将分词提到句首,所修饰主语及所在句子紧跟其后-->形成句首分词修饰句子主语.见OG179

http://forum.chasedream.com/forum.php?mod=viewthread&tid=797540&highlight=%E5%A4%B9%E5%BF%83%E4%BF%AE%E9%A5%B0 这里面都说清楚了