如图所示,木块b放在一固定斜面上,其上表面水平,木块a放在b上.用平行于斜面向上 发布时间:2017-07-04 03:44 │ 来源:www.tikuol.com 题型:选择题 问题: 如图所示,木块b放在一固定斜面上,其上表面水平,木块a放在b上.用平行于斜面向上的力F作用于、b均保持静止.则木块b的受力个数可能是( )A.2个B.3个C.4个D.5个
题型:选择题 The line of people outside the house ____ endless on that morning of the day. [ ]A. isB. areC. wasD. were 查看答案
题型:选择题 如图是位于锦江乐园的摩天轮,一游客乘坐该摩天轮做匀速圆周运动.则( )A.游客在最高点时所需的向心力小于最低点时所需的向心力B.游客在最高点时所需的向心力大于最低点时所需的向心力C.从最高点转到最低点的过程中合外力对游客做功是零D.转动一周的过程中游客的机械能守恒 查看答案
题型:选择题 So excited ____ when he received the invitation to the party that he ____ say a word. [ ]A. was he, didn't B. was he, could hardly C. he was, hardly could D. did he, had to 查看答案