.
Though having discussed it for long, they still haven’t reached an agreement they should pour more money into the project.
A. that
B. if
C. whether
D. what
网友回答
A. that
B. if
(答案→)C. whether
D. what
解析:连词辨析。That因为,以至于;if是否,如果;whether是否,不论;what什么。句意:尽管讨论了很久,他们仍旧没有达成协议,是否他们应该想这个项目投资。If还有如果的含义,用if会引起歧义时,只用whether。如用whether可避免歧义。故选C。