问题
选择题
(2013·南京二模)Though having discussed it for long, they still haven't reached an agreement ________ they should pour more money into the project.
A．whether
B．if
C．that
D．what
答案
答案：A
A 句意：尽管讨论了很长时间，他们依然没有就是否应该把更多的钱投入到这个项目上达成一致意见。根据句意可知用whether引导该同位语从句，if不能引导同位语从句，故选A项。