题目

如图所示，某车沿水平方向高速行驶，车厢中央的光源发出一个闪光， 闪光照到了车厢的前、后壁，则地面上的观察者认为该闪光        （选填“先到达前壁”、“先到达后壁”或“同时到达前后壁”），同时他观察到车厢的长度比静止时变 ▲ （选填“长”或“短”）了。  答案：先到达后壁   短解析:由于车向前运动，地面上的观察者认为该闪光先到达后壁，根据尺缩效应，他观察到车厢的长度比静止时变短 Many years ago, in a small town, there lived a doctor. He was good and kind. At any time of the day and night, he was always ready to go to help a sick person. Everyone in the town liked him and people always went to him when there was anything wrong.   The years went past, and the doctor became old. He began to lose his memory.When people noticed this, they didn’t go to him any more.   “He may give us the wrong medicine,” they said, and they were afraid. The good old doctor noticed that people didn’t come to him any more but didn’t understand why. So he asked, “Why does no one come to me now?”   No one wanted to tell him the real reason because they didn’t want to make the good old man unhappy, so they said, “You have helped all the sick people in the town. There is no one sick now.” The doctor was pleased when he heard that. 1.People always went to the doctor when they were____________. A. wrong     B.not right     C.not well     D.not happy   2. “He began to lose his memory.”means __________. A. He couldn’t know his sick persons any longer. B. He forgot everything in the past. C. He couldn’t find anything. D. He couldn’t remember things well. 3.The sick people didn’t come to the doctor any more because____. A. there was no sick man in the town B. he might give them the wrong medicine C. they were afraid of him D. he was old and no longer a doctor 4. The old doctor was _________ when he heard that there was no one sick in the town. A. sorry     B. angry       C. glad       D. surprised