根据课文解释词语。

1.忧郁_________________________________                                 

2.陶醉_________________________________                         

3.辉煌_________________________________                                 

4.浓厚_________________________________                         

5.兴隆_________________________________                                 

6.弥漫_________________________________                         

7.萦回_________________________________                                

8.心满意足_________________________________           

如图所示，绳长为，小球质量为m，小车质量为M，将m拉至水平右端后放手，则(水平面光滑) （    ）

A．系统的动量守恒

B．水平方向任意时刻m与M的动量等大反向

C．m不能向左摆到原高度

D．M向右移动的最大距离为