one could do something in one's sleep

(informal)one regards something as so easy that it will require no effort or conscious thought to accomplish

(非正式)睡着也能做，不用想也能做完

she knew the music perfectly, could sing it in her sleep.

她非常熟悉这首音乐，睡着也能唱。

get to sleep

manage to fall asleep

设法入睡

go to sleep

fall asleep

睡着

let sleeping dogs lie

(proverb)avoid interfering in a situation that is currently causing no problems but may well do so as a result of such interference

(谚)别多事，别惹麻烦

lose sleep

put someone to sleep

make someone unconscious by using drugs, alcohol, or an anaesthetic

（用毒品、酒精或麻醉剂）使某人失去知觉

put something to sleep

kill an animal, especially an old or badly injured one, painlessly (used euphemistically)

(婉)使（老、幼、重伤动物）无痛死去

sleep easy

sleep like a log (或 top)

sleep very soundly

睡得很香

sleep on it

(informal)delay making a decision on something until the following day so as to have more time to consider it

(非正式)把（问题等）留到第二天再作决定

the sleep of the just

a deep, untroubled sleep

酣睡

sleep rough

sleep tight

[usu. in imperative]sleep well (said to someone when parting from them at night)

睡个好觉（晚上分别时用语）

sleep with one eye open

sleep very lightly, aware of what is happening around one

睁着一只眼睛睡，睡得不好