A-A+
A．Because farmers use less insecticides now.B．
问题详情
A．Because farmers use less insecticides now.
B．Because farmers have been using insecticides for many years.
C．Because insects use the mechanisms against plants to fight insecticides.
D．Because insects have been eating plants for many million years.
参考答案
正确答案：D
解析：昆虫吃植物的历史已经长达两亿五千万年“In fact, insects have been eating plants for as many as 250 million years”，所以它们的抗杀虫剂性能增长得非常迅速。因为它们已经习惯不断进化，对抗各种植物杀虫剂、人工杀虫剂：Now insects are using these same mechanisms to deal with man-made poisons—insecticides...insecticides has develop
