阅读理解 Regeneration of Limbs Most people would agree that it would be wonderful if humans could regenerate limbs. Those who have lost their arms or legs would be complete again. The day is still far off when this might happen. But in the last 10 years, doctors have reported regeneration in smaller parts of the body, most often fingers. Regeneration is not a newly-discovered process. For centuries, scientists have seen it work in some kinds of animals. Break off a lizards (蜥蜴的) tail, for example, and it will grow a new tail. Scientists now are looking for a way to turn on this exciting ability in more highly-developed animals, including humans. Their experiments show that nerves, cell chemistry and the natural electric currents in the body all seem to have a part in this process. The body of every animal contains general purpose cells that change into whatever kind of cells the body needs. Animals such as the lizard or salamander (蝾螈) use these cells to regenerate a new tail or leg when the old one is broken off. These cells collect around the wound. They form a mass called a blastema (胚基). The cells of the blastema begin to change. Some become bone cells, some muscle cells, some skin cells. Slowly, a new part re-grows from the body outward. When completed, the new part is just like the old one. More than 200 years ago, Italian scientist Luigi Spallanzani showed that younger animals have a greater ability to regenerate lost parts than older animals. So do animals lower on the ladder of evolutionary development. The major difference seems to be that less-developed animals have more nerves in their tails and legs than humans do in their arms and legs. Another helpful piece of information was discovered in the late 1800s. Scientists found that when a creature is injured, an electrical current flows around the wound. The strength of the current depends on how severe the wound is and on how much nerve tissue is present. In 1945, American scientist Meryl Rose tested another idea about regeneration. He thought a new limb might grow only from an open wound. Doctor Rose cut off the front legs of some frogs, below the knee. He kept the wounds wet with a strong salty liquid. This prevented skin from growing over the wounds. The results were surprising. Frogs do not regenerate new legs naturally. But these frogs began to grow new limbs. About half of each cut-off leg grew back again. New bones and muscles developed. This research has led doctors to new ways of treating cut-off fingers. Doctors have observed, for example, that many children and some adults will re-grow the top of a finger if the wound is left open.

单选题 The passage indicates that______.

【正确答案】 C

【答案解析】文章对人类肢体的再生并没有一个明确的结论，但从第一段的叙述中使人看到了希望，尤其第一段最后一句说到，最近10年已有人体某些小部位(尤其是手指)再生的报道，而且第二段第三句还说，科学家正在寻找人的肢体再生的方法，使人感到选项C)的推测是有根据的。这一事实也可以说明A)项持绝对否定态度是错误的。D)项也是错误的，因为第一段第三句说“The day is still far off…”(这一天为期尚远…)。而B)项的内容，短文根本没有涉及。

单选题 Which of the following statements is NOT true?

【正确答案】 A

【答案解析】短文第二段第一句和第二句说到(动物肢体的)“再生不是新的发现。几百年来科学家们就见到某些种类的动物就是这样，例如，切断蜥蜴的尾巴，它还会长出新的”，可见选项A)的“lately found”(最近发现)是错误的，也证明了选项B)是正确的。短文第五段最后一句说，“电流的强度取决于伤口有多严重以及多少神经组织”，证明选项C)是正确的。短文第二段第二句说到，蜥蜴的尾巴断了还能长出新的，接着第三句又说，科学家们正在寻找将这种能力用于更高级的动物(包括人)的方法。可见，蜥蜴与人比较，是较低级的动物，故D)项也是正确的。本题问的是哪个是错的，故应选A)。