turn in  提出，返还，睡觉，告密

　　Please turn in your papers by tomorrow. 请你明天把论文交上来。

　　You didn't even read it before you turned it in? 在你提交之前，连读都没读过？

　　She went to the police to turn in a client. 她为了告发客户，去找了警察。

　　I had this room turned into a nursery. 我把这间房改成了托儿所。

　　Come on everyone. Let's turn in.  大家都过来，我们睡觉啦。

　　But I don't feel sleepy right now.  不过我现在一点都不困啊。