In Spite of Hundreds of Millions of Dollars Spent on Insecticides

Multiple Choice

In spite of hundreds of millions of dollars spent on insecticides targeted at pest species,such as mosquitoes and crop pests,we have been unable to drive any to extinction.On the other hand,bird,fish,plant,and insect species that we barely recognize have gone extinct.This has mainly been due to

A) hunting.
B) farming.
C) insecticides such as DDT.
D) habitat destruction.
E) scientific collecting.