问题补充：
—It’s very hot in the room! -- the door open?
A. Why don’t keep
B. Why don’t to keep
C. Why not keep
D. Why not you to keep
答案：
A. Why don’t keep
B. Why don’t to keep
(答案→)C. Why not keep
D. Why not you to keep
解析：句意：--这个室内很热！--为什么不让门开着？分析考查：why don’t you等于why not do故选C
