When you are sleeping you had better all the windows closed.A. don’t keepB. not keepC. no

问题补充：

When you are sleeping, you had better all the windows closed.

A. don’t keep

B. not keep

C. not to keep

D. not keeping

答案：

A. don’t keep

(答案→)B. not keep

C. not to keep

D. not keeping

解析：固定结构had better表示最好做某事，后跟动词原形；其否定形式在动词原形的前面加not即可。结合语境可知是考查had better的否定结构，故选B。