試題詳解

19. When chemicals are used to control unwanted organisms, then the wisest application strategy, in light of natural selection and assuming that chemicals generally have negative effects on the environment, is to apply
(A) a small dose of a single chemical.
(B) a large dose of a single chemical.
(C) moderate doses of several different chemicals.
(D) large doses of several different chemicals.
(E) a moderate dose of a single chemical.