问题补充：
is of no concern to us.
A. It rain or not
B. If or not it rains
C. Whether it rains or not
D. Will it rain or not
答案：
A. It rain or not
B. If or not it rains
(答案→)C. Whether it rains or not
D. Will it rain or not
解析：这题考察whether引导的主语从句,主语从句必须有连接词,AD都没有,B项的if不能和or not连用,句意是:是否下雨和我无关,选C.
