BBC在线收听下载:美国考虑允许9·11遇难者家属起诉沙特政府

短语讲解：

1. The commuter services failed to slow down and crash through the barrier stopping only when it hit the station wall.

slow down（使）慢下来;（使）生产缓慢
例句：The car slowed down as they passed Customs
过海关的时候，车速慢了下来。

2. A US hedge fund has been ordered to pay almost half a billion dollars to settle charges in bribe to officials and a number of African countries to secure mining and investment rights.

a number of 一些;许多的
例句：We have lived here quite a number of years.
我们在这儿住了好些年了。