题目

我们不妨约定：对角线互相垂直的凸四边形叫做“十字形”．（1）在平行四边形、矩形、菱形、正方形中，一定是“十字形”的有．（2）如图1，在四边形ABCD中，AB＝AD，且CB＝CD①证明：四边形ABCD是“十字形”；②若AB＝2．∠BAD＝60°，∠BCD＝90°，求四边形ABCD的面积．（3）如图2．A、B、C、D是半径为1的⊙O上按逆时针方向排列的四个动点，AC与BD交于点E，若∠ADB﹣∠CDB＝∠ABD﹣∠CBD．满足AC+BD＝3，求线段OE的取值范围． Football, to me, is more than just a game. I have probably learned more than valuable lessons from it than from school. When I joined the team freshman year, I didn’t realize what I was getting into. Even though I had been playing since fourth grade and knew it was hard work, nothing would prepare me for the effort I would put into football that year. We worked all summer in the weight room and ran on the track to get in physical and mental shape before the season. See, football is more of a mental sport than anything else, so running on the track wasn’t only about getting in shape . We would push our minds by running as hard as we could even if we felt like we were going to pass out. At the beginning, I was immature (幼稚的) and only thought of myself, sometimes even giving up when I was tired or hurting. Then after the third game I had a season-ending injury. Imagine working all summer and then only being able to play three games! I needed surgery on my arm and at least five months to recover. After freshman year I decided that I would always give my best effort. Playing varsity (大学代表队) football has taught me so much more than just what my tasks are on a particular play or how to block. I have learned to think about others first, and realized how important working hard is. Being with all my friends, even sweating and bleeding with them, really made us unite as a group of hard-working young men, who will succeed in life. 1. What is the text mainly about?    A. How the author dislikes the game of football.    B. When the author began to play football.    C. How the author has changed his attitude to football.    D. What sport the author likes best. 2. The author thinks football is ________.    A. just a game    B. of a mental sport    C. hard to pass out  D. not worth his effort 3. From the text we can infer ________.    A. the author joined the football team with a clear aim.    B. football only brought the author certain tasks    C. the author worked all summer to get ready for the season.    D. the author never lost heart when he met with difficulties. 4. In the third paragraph, the phrase “getting in shape” probably means ________.    A. becoming physically fit             B. designing the playground    C. losing weight                     D. measuring the track