单选题:请根据短文内容,回答题。Endangered SpeciesEndangered species are plants

  • 题目分类:综合类
  • 题目类型:单选题
  • 查看权限:VIP
题目内容:
请根据短文内容,回答题。
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 change of climate and their failure to adapt to such conditions as competition and predation. Since the 1 600s, however, the process of extinction has greatly accelerated as a result of both human population growth and technological encroachment 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 number of reasons, but the primary cause is the destruction of natural habitats. Drainage of wetlands, 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 population crowd into smaller areas,causing further destruction of natural surroundings. Species in these small "islands" lose contact with other populations of their extinction.
Some private and government efforts have been organized to save declining species. Laws were made in some countries in the early 1 900s 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 and support by the people and the courts. Because of 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 w.ho supply the trade, the future of many species is in doubt in spite of legal protection.
According to the passage, which of the following is the most important factor causing the rapid extinction of many species since the 17th century? A.Human beings are not aware of the importance of preserving endangered species.
B.Some endangered species have already reached the end of their life span in evolution.
C.The development of human society has greatly affected natural ecology systems.
D.The world's climate has changed greatly that most species cannot survive.

参考答案:
答案解析:

He hasn't work out the puzzling problem.

He hasn't work out the puzzling problem.A.embarrassing B.surprising C.terrifying

查看答案

在计算机中,每个存储单元都有一个连续的编号,此编号称为(  )。

在计算机中,每个存储单元都有一个连续的编号,此编号称为(  )。A.地址 B.位置号 C.门牌号 D.房号

查看答案

请回答(10)题

请回答(10)题A.south B.source C.saucer D.Sought

查看答案

请回答(5)题

请回答(5)题A.managerial B.manager C.manage D.Management

查看答案

Directions:There are 4 passages in this part.Each of the pas

Directions:There are 4 passages in this part.Each of the passages is followed by

查看答案