Question

You'd better ________ when you come in.

1. A.
   not to wake him up
2. B.
   not wake him up
3. C.
   to not wake him up
4. D.
   not waking him up

Answer 1

B
解析：
had better是復(fù)合情態(tài)動詞，后面只能跟不帶to的不定式；
其肯定或否定意思是通過不定式的肯定或否定形式來表達(dá)的，表示否定意思時，在不定式前加not。