题目

在光滑水平面上有三个完全相同的小球排成一条直线，2、3小球静止，并靠在一起，1球以速度v0射向它们，如图所示。设碰撞过程中不损耗机械能，则碰撞后三个小球的速度是 A. v1= v2 =v3 = v0/3       B. v1=0  v2 =v3 = v0/2 C. v1=0  v2 =v3 = v0/3    D. v1= v2 =0   v3 = v0 答案：D 解析: 略My name is Helen.I come from New York，the USA.Three weeks after my twenty－fourth birthday，I started to work at a children's hospital in California.When I went to work on the first day，I was happy but a little nervous(紧张的)．I said to myself，“Will the children like me？Can I do the job well？” I didn't know what I should say when I saw the children for the first time.I walked into one of the patients'(病人的) rooms.There were three little boys in the room.They smiled(微笑) at me and said hello to me.Then I felt a little relaxed and said hello to them，too.During the next two hours，I talked to them and played games with them happily.I found it was not so hard to get on with the children.That day，I talked with a boy called Bruce for a long time.He got a serious illness．I asked him，“Are you happy here？” He answered，“Yes，but I wished I wasn't ill.” He told me that he liked his school and wished to go to school again.I said I would try my best to help him.Luckily，Bruce got well half a year later.Now Bruce is healthy and he goes back to his school.Now I'm happy to stay with the children and see their happy faces.I really love my job because I can make the children's life better.1.How old was Helen when she started to work at a children's hospital?A. 20. B. 22. C. 24. D. 26.2.How did Helen feel when she went to work on the first day?A. Happy but nervous. B. Happy and relaxed.C. Afraid and nervous. D. Afraid and bored.3.What does the underlined word “illness” in the passage mean in Chinese?A. 态度 B. 治疗 C. 疾病 D. 调查4.From the third paragraph we can learn that Bruce ________ now.A. is seriously ill B. doesn't feel happyC. can't go to school D. is in good health5.Why does Helen love her job?A. Because she can make a lot of money.B. Because she can make the children's life better.C. Because she can play games with the children.D. Because she can help the children with their studies.