题目

一个人用力把一个质量为1 kg的物体,由静止向上提起1 m,这时物体的速度为2 m/s,则下列说法正确的是(    ) A.手对物体做功为12 J                       B.合外力对物体做功为2 JC.合外力对物体做功为12 J                 D.物体克服重力做功为10 J 答案：ABD解析：手对物体做功W=mgh+mv2=12 J,合外力对物体做功W合=mv2=2 J,物体克服重力做功WG=mgh=10 J.The little boy is very kind. He always _____ his food _____ others. [     ]A. share; with B. share; forC. shares; withD. shares; for