问题补充：
It is not to discuss the questions again and again.
A. worth
B. worthy
C. worthwhile
D. worthy of
答案：
A. worth
B. worthy
(答案→)C. worthwhile
D. worthy of
解析：本题考查形容词。worth用法：be worth + n/doing.；worthy用法be worthy of +n/being done；worthwhile用法：It’s worthwhile to do sth/doing sth.句意：这个问题并不值得讨论来讨论去的。
