题干
.
_____ you have a complaint to make, do something about it right away. The longer you wait, the harder it will be to get your complaint resolved.
_____ you have a complaint to make, do something about it right away. The longer you wait, the harder it will be to get your complaint resolved.
A：If
B：Unle
C：Though
D：Since
答案(点此获取答案解析）
A
