标题: prep [打印本页] 作者: Will_Jeanette 时间: 2020-9-9 11:58 标题: prep GMAT_ PREP Test No.9
Prep9-Q4.
Industrialization and modern methods of insect control have improved the standard of living around the globe while at the same time they have introduced some 100,000 dangerous chemical pollutants, having gone virtually unregulated since they were developed more than 50 years ago.
A while at the same time they have introduced some 100,000 dangerous chemical pollutants, having
B while at the same time introducing some 100,000 dangerous chemical pollutants that have
C while they have introduced some 100,000 dangerous chemical pollutants at the same time, which have
D but introducing some 100,000 dangerous chemical pollutants at the same time that have
E but at the same time introducing some 100,000 dangerous chemical pollutants, having
这道题让我很困惑啊，我觉得五个选项一个都不对。。。答案是B，我错选了A，因为觉得while前后的句子要平行，但是同时我也觉得句子末尾的逗号+ving很不妥。。。
想问一下为什么B里面可以直接用ving
谢谢作者: ST5 时间: 2020-9-10 08:46
A. while at the same time they have introduced some 100,000 dangerous chemical pollutants, having xx
里面是SVO, V-ing结构，这里V-ing是不能修饰前面的名词的，修饰的是SVO整个句子(而且要求和Sub有逻辑主语关系），很明显having xx是修饰pollutant，而不是整个句子的。
B里SVO while doing sth这个结构很常见。