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    Coincident with concerns about the accelerating loss of species and habitats has been a growing appreciation of the importance of biological diversity, the number of species in a particular ecosystem( 生态系统., to the health of the Earth and human well-being. Much has been written about the diversity of terrestrial organisms ( 陆生生物., particularly the exceptionally rich life associated with tropical rain-forest habitats. Relatively little has been said, however, about diversity of life in the sea even though coral reef.systems are comparable to rain forests in terms of richness of life. 
    An alien exploring Earth would probably give priority to the planet's dominant, most distinctive feature-the ocean. Humans have a bias toward land that sometimes gets in the way of truly examining global issues. Seen from far away, it is easy to realize that land masses occupy only one-third of the Earth's surface. Given that two-thirds of the Earth's surface is water and that marine life lives at all levels of the ocean, the total three-dimensional living space of the ocean is perhaps 100 times greater than that of land and contains more than 90 percent of all life on Earth even though the ocean has fewer distinct species. 
    The fact that half of the known species are thought to inhabit the world's rain forests does not seem surprising,considering the huge numbers of insects that comprise the bulk of the species. One scientist found many different species of ants in just one tree from a rain forest. While every species is different from every other species, the genetic makeup constrains them to be insects and to share similar characteristics with 750,000 species of insects. If basic, broad categories such as phyla( 门. and classes( 纲. are given more emphasis than differentiating between species, then the greatest diversity of life is unquestionably in the sea. Nearly every major type of plant and animal has some representation there. 
    To appreciate fully the diversity and abundance of life in the sea, it helps to think small. Every spoonful of ocean water contains life, on the order of 100 to 100,000 bacterial cells plus assorted microscopic (极小的. plant sand animals, including larvae( 幼虫. of organisms ranging from sponges and corals to starfish and clams( 蛤蜊.and much more. 
1.[单选题]Why does the author compare rain forests with coral reefs?
  • A.They are approximately the same size.
  • B.They share many similar species.
  • C.Most of their inhabitants require water.
  • D.Both have many different forms of life.
  • 解题思路:根据题干信息compare rain forests with coral reefs可将答案定位到第一段第二、三句。作者之所以将热带雨林生物体系与珊瑚礁生物体系相比较,是想说明它们在物种的丰富性方面类似。故选D,其中的many different forms of life是对原文中richness of life的同义转述。
2.[单选题]The passage suggests that most rain forest species are
  • A.insects
  • B.bacteria
  • C.mammals
  • D.birds
  • 解题思路:根据题干信息most rain forest species可将答案定位到第三段开头处。原文提到: “有一半的已知物种都被认为是生活在热带雨林里的,这种情况似乎不足为奇,只要想想数量巨大的昆虫所构成的这个物种群就明白了。”可见热带雨林中数目最为庞大的一个物种是昆虫。故选A。
3.[单选题]Which of the following conclusions can be drawn from the passage?
  • A.Ocean life is highly adaptive.
  • B.Ocean life is primarily composed of plants.
  • C.The sea is highly resistant to the damage caused by pollutants.
  • D.More attention needs to be paid to preserving ocean species and habitats.
  • 解题思路:根据题干信息可知解答本题需通观全文。文章的主旨是海洋生物多样性很少被关注,作者之所以阐述海洋生物之丰富、数量之庞大,就是为了引起人们对海洋生态的重视。因此可以推断D项 “应该增加对保护海洋物种及其栖息地的关注”是本篇文章所支持的观点。
4.[单选题] The main point of the passage is that
  • A.humans are destroying thousands of species
  • B.there are thousands of insect species
  • C.the sea is even richer in life than the land
  • D.coral reefs are similar to rain forests
  • 解题思路:根据题干信息the main point of the  passage可知解答本题需通观全文。题干问文章的主要观点是什么。作者主要谈的内容就是海洋生物的多样性往往被人们所忽视,人们只知道热带雨林中的物种丰富,却不知占地球表面2/3的海洋的各层水域都有数量巨大的生物体存在,其总量超过陆地生物。答案应为C。
5.[单选题]The author argues that there is more diversity of life in the sea than in the rain forests because
  • A.there are too many insects to make meaningful distinctions
  • B.more phyla and classes of life are represented in the sea
  • C.many insect species are too small to be divided into categories
  • D.marine life forms reproduce at a faster rate
  • 解题思路:根据题干信息there is more diversity of life in the sea than in the rain forests可将答案定位到第三段最后两句。原文提到: “如果从基础的、更宽泛的分类来看,比如重点关注门和纲,而不是区别不同的物种,那么毫无疑问,生物多样性最丰富的将是海洋。几乎每个主要种类的动植物在海洋中都有自己的代表。”选项B是对文中意思的正确概括。
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  • 参考答案:D,A,D,C,B
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