如图所示，A、B是两只相同的齿轮，齿轮A被固定不动，若齿轮B绕齿轮A运动半周，到达图中C位置，则齿轮B上标出竖直向上的箭头所指的方向是[ ]

A．竖直向上

B．竖直向下

C．水平向左

D．水平向右

To the joy of the parents，their only son is now ________ to achieve his goal.[ ]

A．making every effort    

B．making all effort

C．make an effort    

D．sparing no efforts