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题库 / Prep2007E1-SC-97
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.
while at the same time they have introduced some 100,000 dangerous chemical pollutants, having
while at the same time introducing some 100,000 dangerous chemical pollutants that have
while they have introduced some 100,000 dangerous chemical pollutants at the same time, which have
but introducing some 100,000 dangerous chemical pollutants at the same time that have
but at the same time introducing some 100,000 dangerous chemical pollutants, having
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这就算是个外延内涵分词和动词区别的典型题目了吧。后面的having有时间词50years，这说明这个have的动作一定不能包含其主句的动作，因此这里必须用动词。而while后面的at the same time也给出了强烈的同时进行的信号，因此是分词。。
这就算是个外延内涵分词和动词区别的典型题目了吧。后面的having有时间词50years，这说明这个have的动作一定不能包含其主句的动作，因此这里必须用动词。而while后面的at the same time也给出了强烈的同时进行的信号，因此是分词。。