题目

   Li Ming  16  often late for school. The teacher is very angry with him. “  17  are you often late for school?” asks the teacher. “Because I often get up  18  ,” answers Li Ming. “  19  clock can wake you up(叫醒),” says the teacher.” Yes, you are  20  . But it  21  work,” says Li Ming. “Why don’t you  22  it?” asks the teacher again? “Oh, I don’t want it to work  23  ,” answers Li Ming. “If all of us are late for school,   24  do you like it?” says the teacher. “Oh, that’s great! There will be  25  schools in the world,关于物体的机械能，下列说法中正确的是A.高山上的石头，稳稳地静止在那里，它没有重力势能B.运动速度大的物体，具有的机械能不一定就大C.一根弹簧被拉长时具有的弹性势能大，被压缩时具有的弹性势能小D.没有做功的物体一定没有能