问题
选择题
Do you know ______ he will be back?
I'm not sure. But ______ he comes back, I'll call you. [ ]
A. that; if
B. if; that
C. that; that
D. if; if
答案
答案：D
搜题请搜索小程序“爱下问搜题”
Do you know ______ he will be back?
I'm not sure. But ______ he comes back, I'll call you. [ ]
A. that; if
B. if; that
C. that; that
D. if; if
答案：D