题目

下列说法中不正确的是（） A . 在空旷的山谷里叫喊，可以听到回音，这是声音的反射现象 B . 波发生折射时，波的频率不变，但波长、波速均要改变 C . 红外线和X射线都有很强的穿透本领，长用于医学透视 D . 电磁波必须依赖介质传播，不同的介质波速均为v=3.0×108m/s 答案：C,DOne day an Indian went to see his doctor. The doctor looked him over and said, “Medicine won’t help you. You must have a good rest. Go to a quiet country place for a month, go to bed early, drink milk, walk a lot, and smoke only one cigar(雪茄) a day.” A month later, the Indian came to see the doctor again. “How are you?” said the doctor. “I’m glad to see you again. You look much younger.” “Oh, doctor, I feel quite well now,” said the Indian, “I had a good rest. I went to bed early. I drank a lot of milk. I walked a lot. You certainly helped me. But you told me to smoke one cigar a day, and that almost(几乎) killed me at first. It was not easy to begin smoking at my age.” 1.One day an Indian________________.          . A．went to see a friend                     B．felt very tired C．wasn’t feeling well                     D．went to help his doctor 2.His doctor_______.          . A．could not help him                      B．told him what to do C．was good to him                        D．was glad to see him 3.When the Indian came to see the doctor again,_________.          . A．the Indian felt quite well                  B．the doctor wasn’t free C．the Indian was younger                   D．the doctor looked him over again 4.The Indian told the doctor,__________.         . A．he liked doing all those things B．he almost killed him C．to smoke one cigar a day D．one cigar a day was very difficult at the beginning 5.From the story we can guess          . A．the Indian was a young man               B．the doctor was a good doctor C．the Indian would go on smoking            D．the doctor wasn’t very careful