题目

下列说法中正确的是 A．物体间互有弹力时，必有摩擦力B．物体间有摩擦力时，必互有弹力C．只要两物体接触面是粗糙的，接触时必有摩擦力D．两物体只要是接触的，必产生弹力 答案：B 交际运用，从方框中选择适当句子补全对话，其中有一项为多余选项。 A. I had a big meal with my friends. B. I don't feel very well. C. Of course not. D. Nothing serious. E. Certainly I won't. F. I think you ate too much. A: Good morning, doctor. B: Good morning. Sit down, please. What's the matter with you? A:    1    I have a stomachache. B: What did you have for supper yesterday evening? A:    2    We had different kinds of food. B:    3   A: Yes. Is it serious? B: Don't worry.    4    Take this medicine three times a day after meals. Be careful not to eat meat and sea food     these days. A:    5   Thank you, doctor.