质点在恒力F的作用下做曲线运动,P、Q为运动轨迹上的两个点,若质点经过P点的速度比经过Q点时速度小,则F的方向可能为下图中的( )
A:
B:
C:
D:
As I joined the big crowd, I got________from my friends.
We talk in class, so the teacher is ______ angry.
我国国有企业改革的目标是( )