题目

_______is reported in the newspaper, talks between the two countries are making        A.It        B.As    C.That      D.What 答案:B重为100N的物体A,放在水平地面上,在20N水平拉力F作用下,以0.2m/s的速度做匀速直线运动.求:(1)拉力在5s内对物体A所做的功;(2)拉力F的功率.
英语 试题推荐