今天早上，一颗炸弹在伦敦最繁忙的火车站之一爆炸了。

A bomb ___exploded at one of London's busiest railway stations this morning.

他在轮胎里打了太多气，结果它爆炸了。

He put too much air in the tire and it ___exploded.

一颗炸弹爆炸了，那个男孩从事故中救了我。

A bomb had ___exploded and that boy rescued me from the accident.