阅读理解 Passage 2 Endangered Species Endangered species are plants and animals that are in immediate danger of extinction. Extinction is actually a normal process in the course of evolution. Since the formation of the earth, many more species have become extinct than those exist today. These species slowly disappeared because of changes of climate and their failure to adapt to such conditions as competition and predation (捕食). Since the 1600s, however, the process of extinction has greatly accelerated as a result of both human population growth and technological encroachment (侵犯) on natural ecology systems. Today the majority of the world’s environments are changing faster than the ability of most species to adapt to such changes through natural selection. Species become extinct or endangered for a number of reasons, but the primary cause is the destruction of natural habitats (栖息地). Drainage of wetlands (沼泽地), cutting and clearing of forests, growth of cities, and highway and dam construction have seriously reduced available natural habitats. As the various surroundings become fragments, the remaining animal populations crowd into smaller areas, causing further destruction of natural surroundings. Species in these small islands lose contact with other populations of their own kind, thus reducing their genetic variation and making them less adaptable to environment changes. Since the 1600s, commercial exploitation of animals for food and other products has caused many species to become extinct or endangered. Introduced diseases and parasites have also greatly reduced some species. Pollution is another important cause of their extinction. Some private and governmental efforts have been organized to save declining species. Laws were made in some countries in the early 1900s to protect wild animals from commercial trade and killing. International endeavors are shown in the Convention on International Trade in Endangered Species. approved by 51 nations. Its purpose is to restrict exploitation of wild animals and plants by regulating and restricting trade in certain species. How effective such laws will be in various countries, however, depends on enforcement (实施 ) and support by the people and the courts. Because of a lack of law enforcement, the willingness of some segments of society to trade in endangered species, the activities of people who catch and kill animals illegally and dealers who supply the trade, the future of many species is in doubt in spite of legal protection.

单选题 According to the passage, which of the following is the most important factor causing the rapid extinction of man species since the 17th century?

【正确答案】 C

【答案解析】[解析] 细节事实题。根据题干中的时间关键词the 17th century与原文首段第五句中的the 1600s对应，定位答案。题干中的the most important factor与原文中的greatly accelerated对应；题干中的extinction为原文重现；题干中的causing与原文中的as a result of对应，故of后的内容就是答案，其中human population growth and technological被选项C概括为The development of human society，encroachment与选项C中的greatly affected对应，选项C中natural ecology systems为原文重现。故答案为C。

单选题 In the last sentence of the second paragraph, the word islands refers to ?

单选题 This passage mentions all of the following reasons that cause the extinction of man species except?

单选题 According to the passage, which of the following is most important in saving declining species?

【正确答案】 C

【答案解析】[解析] 细节推理题。根据题干中的saving declining species与原文尾段首句中的save declining species(拯救濒危物种)对应，对答案进行定位。仔细阅读原文尾段，第二句中的Laws were made in some countries是重要的措施。再由原文尾段第五句的转折连词however判定本句中的How effective such laws也是重要的方面，此句中的enforcement为选项C中enforced的同根词，support为选项C的重现。故答案为C。