The children should be _____ not to play tricks ______ the disabled. A . educated; on B . trained; to C . educated; with D . trained; on 答案:A关于人对物体做功,下列说法中错误的是……………( )
A.人用手拎着水桶在水平地面上匀速行走,人对水桶做了功
B.人用手拎着水桶从三楼匀速下至一楼,人对水桶不做功
C.人用手拎着水桶从一楼上至三楼,人对水桶做了功
D.人用手拎着水桶站在原地不动,虽然站立时间很长,但人对水桶没有做功