that Dolly was a clone, genetically the same as the adult sheep from which the nucleus came. Such a development means a lot to the cloning field.

　　Dolly lived to be 6.5 years old and died in 2003 from a type of lung cancer that is caused by a virus and affects sheep. Before her death, Dolly developed arthritis (关节炎) at a relatively young age and had trouble walking. This caused concerns that clones might be at increased risk for age­related diseases, the researchers said.

　　In the new study, 13 cloned sheep underwent a series of health tests. The test results were normal for the sheep's age. Some of the sheep had signs of mild arthritis, but this would be expected in older sheep and was not detrimental,_so none of the sheep needed treatment for the condition, the researchers said.

　　The cloning process itself comes with a high risk of death in the fetus (胎儿). But for the clones that survive, the new data suggests that "they are healthy and seem to age normally"．

　　语篇解读：本文讲述了克隆羊多莉及其"姐妹"的情况。研究发现，那几只跟克隆羊多莉的基因一样的克隆羊没有出现大的健康问题。

　　1．What do the findings of the new study mainly suggest?

　　A．Sheep can be genetically the same.

　　B．Cloned animals can't live longer than normal ones.

　　C．Scientists can help prevent diseases in cloned animals.

　　D．Cloned animals aren't at higher risk for age­related health problems.

　　解析：选D　推理判断题。根据第一段的"the first cloned mammal, are still healthy even in old age, a new study found"可知，这个研究表明年龄大的克隆动物患病的几率并不会更高。

　　2．What do we learn about the sheep Dolly from the text?

　　A．Her birth led to the creation of SCNT.

　　B．Her birth was a great scientific achievement.

　　C．Her genes were unique when she was created.

　　D．Her genes were created using a normal technique.

　　解析：选B　推理判断题。根据第一段的"Dolly, the first cloned mammal"以及第三段的"Dolly was born in 1996 as the result of a lab technique called somatic­cell nuclear transfer (SCNT)"可知，多莉的诞生是一个科学上的成就。

　　3．When Dolly died, scientists most probably ________.

　　A．became worried about the health of cloned animals

　　B．thought her death was caused by old age

C．found a way to reduce the risk for age­related diseases