题目

John shut everybody out of the kitchen. It seemed _____ he wanted to prepare a grand surprise for the party.   A. which                          B. when                               C. so that                                      D. as if 答案：D 物体在水平恒力作用下，在水平面上由静止开始运动当位移s时撤去F，物体继续前进3 s后停止运动，若路面情况相同，则物体的摩擦力和最大动能是 A． B． C． D．