Many entomologists say that campaigns to eradicate the fire ant in the United States have failed because the chemicals that were used were effective only in wiping out the ant’s natural enemies, which made it easier for them to spread. A. which made it easier for them B. which makes it easier for it C. thus making it easier for them D. thus making it easier for the ant E. thereby, it was made easier for the ant
,翻了原来的讨论稿，没见讨论过这个问题。