Question

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

Answer 1

B

Step-by-step explanation:

Hi! The answer to your question would be option B "while at the same time introducing some 100,000 dangerous chemical pollutants that have". This is because while is a good connector between the two sentences (qhich eliminates D and E). Also, the verb introduce has to be present and ongoing (introducing), which rules out A and C. Therefore, B is your answer