问题补充:
—Uncle John is badly ill these days.
—Sorry to hear that. he leaves the bad factory, he won’t be able to get better.
A. If
B. Though
C. Since
D. Unless
答案:
A. If
B. Though
C. Since
(答案→)D. Unless
解析:If是否,如果;Though虽然,尽管;Since由于,自从……以来;Unless除非,如果不。句意:约翰叔叔这些天病得很厉害。——很遗憾听到这个消息。如果他不离开这家糟糕的工厂,他不会好起来。结合语境可知选D。