题目

I really don’t know what kind of man he really is ; on one ________, he is normal , and on another , he acts crazily . A.      situation       B. occasion     C. position    D. condition 答案：B物体m放在倾角为α的斜面上保持静止状态，当α逐渐减小的过程中(可认为物体始终处于平衡状态)，斜面对物体的作用力A.减小B.不变C.增大D.无法确定