他躺在地板上呻吟着。

He lay on the floor ___moaning.

他呻吟着抱怨，但没有任何明显的外伤迹象。

He ___moaned and groaned but he did not have any obvious signs of injuries.

手术后，她因疼痛忍不住轻声呻吟。

After the surgery, she couldn't help but ___moan softly from the pain.