问题
选择题
The policy of the mainland is very clear and straightforward，and the key problem is ______ the leaders of Taiwan will accept it.
A．that
B．how
C．why
D．whether
答案
答案：D
句意：大陆的政策很清楚也很直接，关键问题是台湾领导人是否接受。由句意可知，要用whether(是否)引导这个表语从句。