例句：
I sleep with the window open unless it's really cold.
天气若不很冷，我总开着窗户睡觉。
He works at night and sleeps during the day.
他晚上干活，白天睡觉。
How long can a human being go without sleep?
人不睡觉能活多久？
He took a long time getting to sleep that night.
他那天晚上过了好长时间才睡着。
You'll feel better for a good night's sleep.
你晚上睡个好觉就会觉得好些。