A．cloning has already been used to treat heart disease

　　B．we can treat a man's heart disease by cloning hearts

　　C．most people in industrial countries suffer from heart disease

　　D．more people die of heart disease than of other diseases in the US

　　解析：选D　细节理解题。根据第三段最后一句可知，心脏病是美国和其他工业化国家的头号杀手，因此在美国死于心脏病的人要比死于其他疾病的人多。

　　3．What is the main idea of the last paragraph?

　　A．With cloning infertile couples could have children.

　　B．Treatment of infertility is not successful.

　　C．Infertile couples suffer a lot physically and mentally.

　　D．It is difficult for couples to have more children now.

　　解析：选A　段落大意题。联系全文可知，本文的主题是人类克隆技术。最后一段点明了现在治疗不孕的成功率很低，许多夫妇饱受煎熬，最后说明了利用人类克隆技术可以使不孕的夫妇有自己的孩子，因此A项正确。

　　4．What is the author's attitude towards human cloning?

　　A．Supportive.　　　　　　 B．Doubtful.

　　C．Cautious. D．Curious.

　　解析：选A　推理判断题。根据文章第一句，特别是关键词benefit及第二至五段(都是讲人类克隆技术会给人类带来益处)可推知，作者对人类克隆技术持支持的态度。

　　B

　　I'm sure many of you have seen Star Wars, Jurassic Park, Multiplicity, or many of the other movies that describe cloning. Most of what you see in these movies is false. What you don't know is that cloning could be dangerous, to the clone and to our society as a whole. It's immoral to have a human clone.

　　What about identity? Humans are promised the right to their own personalities. What would happen if we ignore those rights by giving them someone else's genetic identity? True, personality is not fixed in genetic fault of the cloned.

　　Also, there is a large power struggle here. Cloning means a degree of power and control over another person's physical identity and that ignores their rights and their only personalities. The person doing the cloning would have more power than any parent would have.

Cloning would also deal with killing embryos (胚胎). You might not have known, but Dolly, the sheep that was cloned in 1996, was one of over 200 sheep embryos and hers was the only embryo that survived. The rest died or were thrown away. Imagine if the failure rate was that high