问题
选择题
I don't know ____. [ ]
A. what to do it
B. how to do it
C. to do what
D. how to do
答案
答案：B
搜题请搜索小程序“爱下问搜题”
I don't know ____. [ ]
A. what to do it
B. how to do it
C. to do what
D. how to do
答案：B