他重重地摔了一跤，伤了背部。

He had a nasty ___fall and hurt his back.

巨石在坠落过程中撞倒了几棵小树。

The boulder smashed several small trees during its ___fall.

我很害怕，然后听到旁边有坠落的声音。

I was terrified and I heard the noise of a ___fall just by my side.