—Did anyone support you at the meeting?

—Moore was the only person who __________ my opinion.

A．agreed

B．cared

C．shared

D．accepted

如图所示，质量为m的物体在三个共点力作用下处于平衡状态，若把方向向东的力F撤去，其余两个力的大小及方向均保持不变，则这个物体的加速度大小为________，方向为___________。