Industrialization and modern methods of insect control have improved thestandard of living around the globe while at the same time they haveintroduced some 100,000 dangerous chemical pollutants, having gonevirtually unregulated since they were developed more than 50 years ago.
(A) while at the same time they have introduced some 100,000 dangerouschemical pollutants, having
(B) while at the same time introducing some 100,000 dangerouschemical pollutants that have
(C) while they have introduced some 100,000 dangerouschemical pollutants at the same time, which have
they有指代不清的嫌疑;用which非限定性定语从句改变句子原意
(D) but introducing some 100,000 dangerous chemical pollutants at the sametime that have
(E) but at the same time introducing some 100,000 dangerous chemicalpollutants, having
我不明白C的they为什么会有指代不清,they不就是指代前面的主语Industrialization and modern methods么? |