2017届高三英语一轮复习 Unit 2 Cloning练习 新人教版选修8.doc

Unit 2　Cloning 阅读理解·组块专练——练速度 (限时：35分钟) Ⅰ.阅读理解 A Have you seen Jurassic Park? In this film, scientists use DNA kept for tens of millions of years to clone dinosaurs. They find trouble, however, when they realize that the cloned creatures are smarter and more dangerous than expected. Thats nothing more than a fiction. But could we really clone endangered animals? To date, the most successful attempt to do so was the cloning of a gaur, a rare ox-like animal from southeast Asia. Scientists used a cow to bring the cloned baby gaur, named Noah. Two days after birth, however, Noah died from a common bacterial infection. Other endangered species that may be cloned include the African bongo antelope (羚羊), the Sumatran tiger, the cheetah (猎豹), and the giant panda. Next, could we really clone extinct animals? In theory? Yes. To do this, you need a well-kept source of DNA from the extinct animals such as wool mammoth (毛象), Tasmanian tiger, or even dinosaur, and a closely related species, still living, which could serve as a_surrogate_mother. In reality? Probably not. On the one hand, its not likely that extinct animals DNA could survive undamaged for such a long time. Cloning such extinct animals as wool mammoth, Tasmanian tiger, or dinosaur is much more difficult due to the lack of properly well-preserved DNA. On the other hand, for example, a gaur can have a cow as a surrogate mother, definitely not a monkey. But what about an extinct animal as unique as the panda? What species could possibly serve as a surrogate mother? Cloning presents many exciting possibilities. However, even if extinct animals were brought back, they could not survive in todays world. Not only do most extinct animals have no habitat to live in, but the other plants and animals they depended on for food may also be gone as well. 语篇解读：本文说明了在克隆灭绝动物的过程中遇到的重重困难与障碍。即使克隆成功了，其赖以生存的食物链也已经被破坏，被克隆出来的动物也无法继续生存下去。 1．It can be learned from the text that ________. A．the gaur is an extinct species B．the gaur lives in