题目

在水平地面上，A、B两物体叠放如图所示，在水平力F的作用下一起匀速运动．若改将水平力F作用在A上，两物体可能发生的情况是A．A、B一起匀速运动    B．A加速运动，B匀速运动C．A加速运动，B静止    D．A与B一起加速运动  答案：AC解析:略  你什么时候到的？我昨天晚上到的。 [    ] 　　A. ----When have you arrived? 　　 ----I have arrived yesterday evening. 　　B. ----When did you arrived? 　　 ----I arrived yesterday evening. 　　C. ----When were you arriving? 　　 ----I arrived yesterday evening. 　　D. ----When did you arrive? 　　 ----I arrived yesterday evening.