释义：
stay in 留在某处
stay in something 表示“留在……的内部”，相反 stay out 表示“不进入某处，留在外面”。
例句：
We'll stay in the car. I'll be right back.
你们待在车里。我去去就来。
I can stay out as late as I want.
我可以一直待在外面，想几点回去就几点回去。
It's best you stay in there.
你能留在这里简直太好了。
Let's stay outside for a while.
我们出去待一会儿吧。
对话：
A: Look at that rain. I'm going to stay in today.
瞧瞧这雨，我今天要在屋里待着。
B: Me too. I don't want to get wet.
我也是，我可不想变成落汤鸡。