模拟试题（七） Part I Reading Comprehension (40% 35minutes) Directions: In this part there are four passages. Each passage is followed by a number of comprehension questions. Read the passage and choose the best answer to each question. Then, mark your answer by blackening the corresponding letter on the Answer Sheet. Questions 1 to 5 are based on the follow ing passage: Suppose we built a robot (机器人) to explore the planet Mars. We provide the robot with seeing detectors (探测器) to keep it away from danger. It is powered entirely by the sun. Should we program the robot to be equally active at all times? No. The robot would be using up energy at a time when it was not receiving any. So we would probably program it to stop its activity at night and to wake up at dawn the next morning. According to the evolutionary (进化的) theory of sleep, evolution equipped us with a regular pattern of sleeping and waking for the same reason. The theory does not deny (否认) that sleep provides some important restorative functions (恢复功能). It merely says that evolution has programmed us to perform those functions at a time when activity would be inefficient and possibly dangerous. However, sleep protects us only from the sort of trouble we might walk into; it does not protect us from trouble that comes looking for us. So we sleep well when we are in a familiar, safe place, but we sleep lightly, if at all, when we fear that bears will nose into the tent. The evolutionary theory explains the differences in sleep among creatures. Why do cats, for instance, sleep so much, while horses sleep so little? Surely cats do not need five times as much repair and restoration as horses do. But cats...
