题目

Qβ噬菌体的遗传物质（QβRNA）是一条单链RNA，当噬菌体侵染大肠杆菌后，QβRNA立即作为模板翻译出成熟蛋白、外壳蛋白和RNA复制酶（如图所示），然后利用该复制酶复制QβRNA。下列叙述正确的是 A.QβRNA的复制需经历一个逆转录的过程      B.QβRNA的复制需经历形成双链RNA的过程 C.一条QβRNA模板只能翻译出一条肽链        D.QβRNA复制后，复制酶基因才能进行表达四、阅读理解（本题有两节，共16小题，每小题2分，共32分）第一节：阅读下列材料并做后面的题目。从每题多给的A、B、C、D四个选项中，选出最佳答案。 AI was walking along Orchard Road when I realized a tall young man wearing a jacket and tie was following me. I noticed him because not many people wear a jacket and tie in the middle of a hot summer day, and I had already seen this man four times that afternoon. To make sure he was following me, I walked on quickly, turned right into a shopping center and then stopped to look in a shop window. Soon the man appeared and stopped at another shop window. I walked on and stopped several times. When I stopped, he stopped too. I began to be rather worried and decided to try to lose this strange man. When I saw a taxi coming, I jumped into it. As I was telling the taxi driver where to go, I found the man get into another taxi, which then followed mine. As the two taxies slowly made their way along Orchard Road, I looked back at the taxi behind, and saw that the stranger was looking out at me. At MRT station, I told the taxi driver to stop and I got out. As I was paying my fare, I saw the man was getting out of his taxi. By now I got angry, so I turned and walked straight to him. I asked him why he was following me.  At first he said he was not following me at all, but when I threatened(威胁) to call the police, he admitted he was. He then told me that he was a news reporter and that he was writing an article on how elderly people in Singapore spend their time. He said he was observing me to gather materials for his article. 46. What is strange about the man who followed the writer? A. He seemed to be wearing too much.           B. He was out on such a hot day. C. He walked quickly behind.                      D. He was a tall young man. 47. What did the stranger do when the writer jumped into a taxi? A. He got into another taxi.                         B. He tried to stop the taxi. C. He almost gave up following him.             D. He made his way along Orchard Road. 48. How did the writer have the stranger admit(承认) he was following him? A. He threatened to take him to the police.            B. He called the police. C. He said he would call the police.                             D. He talked to the police. 49. Why did the stranger follow the writer? A. He was interested in elderly people.                  B. He often does such things. C. He was writing a book about young people.          D. He needed materials for his article.