第二节(共10小题;每小题1. 5分,满分15分)

阅读下面材料,在空白处填入适当的内容(1个单词) 或括号内单词的正确形式。

            Reproductive cloning may enable researchers to make copies of animals with potential benefits for the field of medicine and many others.

            For instance,the Scottish researchers who cloned Dolly have also cloned other sheep that have been genetically changed

61. (produce) milk that contains a human protein essential for blood (凝固) .They did this in the hope 62.someday this protein may be obtained from the milk and given to humans 63.blood doesn’t clot properly.

            64. application is to create clones to build populations of endangered,or possibly even extinct species of animals. In 2003,an endangered type of ox,called the banteng,was successfully cloned. 65.(short) after that,three African wildcats' were cloned using frozen embryos as a source of DNA. Some experts are 66. favour of cloning extinct animals,saying that it can save many species that would otherwise disappear,while some raise a(n) 67.(object) , arguing that cloning produces a population of genetically identical individuals that lack the genetic variability necessary for species survival.

            Some people have even expressed interest in 68. (have) their deceased pets cloned in the hope of getting a similar animal to replace the dead one. But as 69.(show) by a cloned cat,a clone may not turn out exactly like the original pet whose DNA 70.(use) to make the clone.

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