【正确答案】 C

【答案解析】[听力原文]14-16 What is cloning? Cloning is the creation of cells or whole animals using DNA from a single "parent", bypassing the normal reproductive process. The clone has the same DNA as the parent. The most common process takes DNA from one cell and puts it in a hollowed-out egg. Chemicals and electricity are then used to encourage the new DNA to fuse with the egg and develop into an embryo. This technique is called nuclear transfer. The first cloned animal in human history was a sheep called Dolly. It was very important because it was the first mammal to be cloned using DNA taken from an adult cell. Previously, animals had only been cloned using embryo cells, which already have the potential to become complete embryos in their own right. The big breakthrough with Dolly was that a clone was made from an ordinary, adult cell. When it comes to the question of whether cloned animals are normal and healthy, the answer is YES. Dolly is, but scientists do not yet know whether this is the exception or the rule. Some early evidence suggests that clones may have health problems and that they may age prematurely. With the birth of Dolly, many people are worried that a human clone may be born soon. It's possible in theory. But the technology of reproductive cloning is still in its very early stages and there is much that scientists do not understand. What's more, human cloning is already banned by law in the United Kingdom. The former President of the United States, Bill Clinton, proposed banning research into producing human clones in the U. S. for five years. Some measures have also been taken to establish international agreements banning live human clones.