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

A．Exploitation.

B．Pollution.

C．Habitat alteration.

D．Congressional law.

关于黑社会性质组织的特征，下列说法哪些是正确的？（）

A.形成较稳定的犯罪组织，人数较多，有明确的组织者、领导者，骨干成员基本固定

B.有组织地通过违法手段获得经济利益，具有一定的经济实力，以支持该组织的活动

C.以暴力、威胁或者其他手段，无组织地多次进行违法犯罪活动，为非作恶，欺压、残害百姓

D.有时候不需要利用国家工作人员的包庇