题目

在基因工程中使用的限制性核酸内切酶，其作用是（ ） A . 将目的基因从染色体上切割出来 B . 识别并切割特定的DNA核苷酸序列 C . 将目的基因与运载体结合 D . 将目的基因导入受体细胞 答案：B A rich Japanese was on vacation in New York. One day he went into a shop. He wanted to buy a nice-looking watch very much, but the owner of the shop asked five hundred dollars for it. Suddenly a young man came into the shop, took the watch out of the owner’s hands and ran out with it. It all happened in a few seconds. When the owner ran out into the street, the young man already disappeared (消失) among the people.The rich man went on. At the next corner, he saw the young man with the stolen watch in his hand. “Do you want to buy a fine watch, sir?” he asked in a low voice, “It’s only a hundred dollars.” “The young man doesn’t know I saw him stealing the watch,” he thought. The rich man paid him at once and went back to his room with the watch. He told his friend about the fine watch.His friend had a look at the watch and began laughing. He said, “You are foolish. This watch isn’t worth (价值) even ten dollars. I’m sure the shop owner and the young man planned this play together.”1.Which country did the rich Japanese travel to?A.The UK. B.The USA. C.France. D.Australia.2.The owner of the shop asked dollars for the watch.A.500 B.250 C.100 D.1503.The rich Japanese bought the watch from .A.the shop owner B.his friendC.the young man D.the people in the street4.The rich man’s friend began laughing because .A.the watch was nice B.the watch was really cheapC.he had a watch like that D.he thought the rich man was foolish5.From the story, we can learn that may be dishonest.A.the rich man’s friend B.the shop ownerC.the young man D.both B and C