题目

如图所示，A、B两物体置于水平地面上的O点，物体C置于P点，轻弹簧左端与竖直墙壁连接，右端与物体A相连，此时弹簧处于原长状态，物体B与A接触但无挤压。已知O点左侧水平面光滑，右侧粗糙，与物体A、B、C间动摩擦因数均为μ，物体A的质量为m1=m，物体B的质量为m2=5m，OP两点之间的距离为d。对物体B施加向左的外力，缓慢将AB推动到Q点（图中未画出），撤掉外力，物体B刚好滑动到P点但未与物体C发生碰撞。物体A、B、C均可视为质点，求： （1）完形填空On Sunday morning, I usually get up very late. I wash my face, and then go out to do morning exercises. It is about 8: 40 am. After I eat my________ , I often go to a shopping centre________ my mother. The shopping centre is ________our home, so we walk there. It takes us about 20 minutes to get there. The shopping centre has a good ________ . It is called“蓝莓购物中心”in Chinese. It doesn’t have an English name. Can you________ it in English? It is new and big. There are many things there, such as TVs, fridges, computers, clothes, food________ drinks. There are many ________ every day. There are men and women, the old and the________ . ________ do many people come here to buy things? Do you know? Let me tell you. The workers there are always nice and friendly. The things there are usually good but not _______ . If you come to my home, I can take you there and have a look.1.A. breakfast B. lunch C. supper D. dinner2.A. for B. to C. of D. with3.A. near B. into C. at D. from4.A. flower B. place C. name D. room5.A. say B. speak C. tell D. talk6.A. but B. with C. or D. and7.A. students B. people C. children D. teachers8.A. tall B. short C. young D. small9.A. What B. Who C. Why D. When10.A. expensive B. cheap C. big D. New