如图所示，弹簧振子在a、b两点间做简谐振动当振子从平衡位置O向a运动过程中（   ）

请根据句意从方框中选择合适的单词，并用其适当形式填空，使句子通顺。

____ This shop sells all kinds of    ▲   from different countries.
____ I hear that her uncle has bought a new flat in the city centre    ▲   .
____ Jack won the    ▲   prize in the school reading contest and he felt very excited.
____ He had to make a    ▲   between staying with his parents and going abroad. 
____ You know Mike’s hobby is playing football, but    ▲   is collecting stamps.

质量为1 kg的小球从空中某处自由下落，与水平地面相碰后弹到空中某一高度，其速度随时间变化的关系如图所示，取g＝10 m/s²，则  (　　)