Since life began eons ago, thousands of creatures have come and gone. Some, such as the dinosaurs, became extinct due to natural

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问题     Since life began eons ago, thousands of creatures have come and gone. Some, such as the dinosaurs, became extinct due to naturally changing ecologic conditions. More recent threats to life forms are humans and their activities. Man has drained marshes, burned prairies, dammed and diverted rivers. Some of the more recent casualties of man’s expansion have been the dodo, great auk, passenger pigeon, Irish elk, and Steller’s sea cow. Sadly, we can no longer attribute the increasing decline in our wild animals and plant species to "natural" processes. Many species are dying out because of exploitation, habitat alteration or destruction, pollution, or the introduction of new species of plants and animals to an area. As mandated by Congress, protecting endangered species, and restoring them to the point where their existence is no longer jeopardized, is the primary objective of the U.S. Fish and Wildlife Service’s Endangered Species Program.
Which of the following is NOT a cause of increasing decline of wild animal population?

选项 A、Exploitation.
B、Pollution.
C、Habitat alteration.
D、Congressional law.

答案D

解析 文中提到Many species are dying out because of exploitation,habitat alteration or destruction, pollution,or the introduction of new species of plants and animals to an area.许多物种灭绝是由于人类的开发,栖息地的变更或毁灭,污染或新的动、植物物种的传人。因此选项A. exploitation、B. pollution和C.habitat alteration均是导致野生动物总数持续下降的原因,只有选项D.Congressional law不是原因,故是本题答案。
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