我听见门后传来他的呻吟声。

I could hear his ___groan from behind the door.

之后，随着一声狂野的呻吟，他倒在地上。

Afterwards, with a wild ___groan, he dropped down to the ground.

听到这个坏消息时，她不由得发出一声呻吟。

A ___groan escaped her lips when she heard the bad news.