问题
选择题
The earth will become worse and worse ______ we do something to stop her from being polluted. [ ]
A. if
B. even if
C. when
D. unless
答案
答案：D
搜题请搜索小程序“爱下问搜题”
The earth will become worse and worse ______ we do something to stop her from being polluted. [ ]
A. if
B. even if
C. when
D. unless
答案：D