The question we can get enough coal for the winter has not been cleared up yet .A. thatB.

问题补充：

The question we can get enough coal for the winter has not been cleared up yet .

A. that

B. if

C. which

D. whether

答案：

A. that

B. if

C. which

(答案→)D. whether

解析：考查名词性从句。本题考查同位语从句，解释说明the question，不可用if。句意：冬天我们是否有足够的煤，这个问题还不明晰。