Question

-- It's very hot outside.
---Why          you stay at home?
A. not         B. not to     C. don't

Answer 1

C

试题分析：根据语境可知此句考查的是固定句型结构why don’t you do sth意思是为何不…表示的是建议相当于why not do sth。故选C。
点评：表示建议的句型结构很多，常用的是why not do sth，shall we do sth，you’d better do sth和let’s do sth等.