高三英语一轮复习题型（说明文阅读2篇 夹叙夹议文七选五 语法填空 应用文写作）精准练（DAY 28）.docVIP

高三英语题型精准练（DAY 28） 目录 内容 Section A 说明文阅读 Section B 说明文阅读 Section C 夹叙夹议文七选五 Section D 语法填空 Section E 应用文写作 Section A： Section A：说明文阅读 The news that researchers have used cloning to make human embryos for the purpose of producing stem cells may have some people wondering if it would ever be possible to clone a person.Although it would be immoral,experts say it is likely biologically possible to clone a human being.Since the 1950s when researchers cloned a frog,scientists have cloned dozens of animal species,including mice,cats,sheep,pigs and cows. With mice,researchers are able to use thousands of eggs,and conduct many experiments,to work out these problems.“It’s a numbers game,” said Dr.Robert Lanza,the chief scientific officer at a biotech company.“But with primates (灵长类动物),eggs are very precious,and it is not easy to get them to conduct experiments.” In addition,researchers can’t simply apply what they’ve learned from cloning mice or cows to cloning people.Cloning an animal requires that researchers remove proteins that are necessary to help cells divide.In mice,this isn’t a problem,because the embryo that is created is able to make these proteins again.But primates aren’t able to do this,and researchers think it may be one reason that attempts to clone monkeys have failed. What’s more,cloned animals often have different kinds of abnormalities.These abnormalities are common because cloned embryos have just one parent rather than two,which means that a process known as “imprinting (印记)” does not occur properly in cloned embryos. “Problems with imprinting can result in extremely large embryos,which leads to problems with blood flow for the baby,” Lanza said.“The extremely high rate of death and the developmental abnormalities from cloning make cloning people immoral.It’s like sending your baby up in a rocket knowing there’s a 50-50 chance that it’s going to explode.” 1.What can we learn from Paragraph 1?　　　　　　　　　　　　　　　 A.Animal cloning is illegal. B.Human cloning is