他跌倒在地，痛苦地呻吟着。

He fell to the ground and was ___groaning in pain.

员工们抱怨着加班太多。

The employees were ___groaning about working overtime too much.

沉重的行李箱压在架子上，发出吱呀吱呀的声音。

The heavy suitcase made the shelf ___groan under its weight.