Definition: when someone is sleeping in a way that makes it difficult to wake them up Level: B2
他陷入了沉睡。
He fell into ___a ___deep ___sleep.
然后，他陷入了沉睡，把包放在旁边。
Then, he fell into ___a ___deep ___sleep, placing his sack next to him.
长途徒步后，她沉睡不醒，没听到闹钟。
After the long hike, she was in ___a ___deep ___sleep and didn't hear the alarm.
