题目

如图,在边长为1的正方形组成的网格中,△AOB的顶点均在格点上,其中点A(5,4),B(1,3),将△AOB绕点O逆时针旋转90°后得到△A1OB1. （1） 画出△A1OB1； （2） 在旋转过程中线段OB扫过的图形的面积为. 答案：解：如图所示，△A1OB1即为所求； 【1】2.5πCharlie works in a post office. His father lost his job five years ago and his mother is often ill. And he has two brothers and a sister. He works hard and tries his best to buy enough food for his family. Last month his family had to move to an old house outside the city. It’s far from the post office and he has to get up early in the morning in order to catch the 6: 30 train. The head of his office is strict and everybody has to get there on time. He knows what it’ll mean if he’s late. A friend of his had pity on(同情) him and lent his old car to him. The young man was happy and from then on he could go to work by car. Last Saturday Charlie went to buy some medicine for his mother. Bad luck! When he came out of the shop, he couldn’t find the car. He was quite worried and began to look for it in front of the shop but he didn’t find it. Suddenly he saw a woman parked a car there and hurried into the shop. Charlie saw the car wasn’t locked. He got on it and drove it at once. He was afraid the loser would run after(追) him and drove fast. A truck hit it at a crossing and he lost consciousness. This morning the young man came back to life(苏醒) and saw there were a few policemen standing by his bed. He asked, “Where am I? ” “In Room 103. ” “In hospital or in prison(监狱)？” 1. Charlie has to get to his office on time because______. A. the head is strict with them B. he wishes to be praised C. he’s usually on duty D. he’s afraid to be fired 2. ______, so he drove the woman’s car away. A. Charlie had no money to pay for the old car B. Charlie liked a new car very much C. Charlie hoped to have his own car D. Charlie hated his friend’s old car 3. Charlie was afraid______, so he drove fast. A. to be late B. to meet the red lights C. to be caught by the loser D. to miss the 6: 30 train 4. Which of the following is true? A. Charlie couldn’t drive a car at all. B. The policemen caught Charlie at the crossing. C. Charlie was in prison when he came back to life. D. Charlie didn’t know what had happened after he had lost consciousness.