—Is this __________ ruler?

—No, it’s my ruler. __________ is over there.

A．hers; Her

B．her; Hers

C．hers; Her

D．her; Hers

力的定义：物体与物体间的                      叫做力。力的作用效果有两个方面：①使物体发生形变；②改变物体的速度。平常所说物体的运动状态发生变化是指物体的                     发生了变化。