题目

如图，轻质弹簧一端固定在斜面（固定）底端的O点，弹簧处于原长状态时，对应的斜面OP部分光滑，斜面顶端Q至P的斜面部分粗糙．一滑块从斜面顶端Q处释放，接触弹簧并压缩，弹簧始终处于弹性限度内，滑块与弹簧作用时不损失能量， 从滑块开始运动至压缩弹簧最短的过程中，下列说法正确的是： A. 滑块减少的重力势能大于弹簧最大弹性势能 B. 滑块、弹簧、地球构成的系统，机械能守恒 C. 滑块先做匀加速后做匀减速直线运动 D. 滑块接触弹簧以后完型填空（仔细阅读上下文，从A、B、C、D中选出最佳答案共10分）Mr. Ellis is very old. He has seen__ __ changes in his home town. He knows that things are different now. But he never forgets the old days. He likes to talk about them. He often talks about his favourite _ __, the robins (知更鸟). "When I was a boy, these houses were not here. There were wide fields and tall trees. Every spring the robins would come. Thousands of them would fly up to the north from the south. They spent the in the south. Some would build their nests (巢) in the near our houses. We knew it was spring when the robins came. When they left , we knew winter __ .“Then people building more houses. They cut down trees and they filled the fields ___ _ houses. The robins stopped _ back. Oh, we’d seen some once in a while , but they couldn't find a right place their nests near our houses because there were no trees.""Now there are lots of houses and roads. There are no area for the robins. They do not come any more, which is sad."1.A. too much B. much too C. many D. many too2.A. animals B. houses C. birds D. days3.A. spring B. summer C. autumn D. winter4.A. trees B. fields C. parks D. buildings5.A. left B. came C. reached D. got6.A. stopped B. went C. started D. came7.A. of B. with C. in D. up8.A. returning B. flying C. to return D. to fly9.A. to build B. building C. to live D. to live in10.A. building B. feeding C. hunting D. living