sleep与sleeping区别
如He have to sleep by day and work by night.他只好白天睡觉，晚上工作。
2.sleeping用作系动词，接形容词作表语。
如Her arm pillowed the sleeping child.熟睡的孩子枕着她的手臂。
例句
He slipped unawares into sleep.
他不知不觉地睡着了。
REM sleep is termed \'active\' sleep.
快速眼动睡眠称作“主动”睡眠。
We unrolled our sleeping bags.
我们打开了睡袋。
This sleeping bag is very warm.
这条睡袋很暖和。
The baby was sleeping peacefully.
婴儿睡得很安稳。