他咕哝着说不想出去。

He ___mumbled that he wasn't interested in going out.

她含糊地道了个歉，迅速离开了房间。

She ___mumbled an apology and quickly left the room.

别咕咕哝哝的，说清楚点，这样我才能听懂！

Stop ___mumbling and speak clearly so I can understand you!