他重重地摔了一跤，伤到了后背。

He had a nasty ___fall and hurt his back.

这块巨石在滚落过程中砸断了好几棵小树。

The boulder smashed several small trees during its ___fall.

我听到走廊里传来一声很响的跌倒声，赶紧跑去看发生了什么事。

I heard a loud ___fall in the hallway and rushed to see what happened.