They are having debate about whether the two countries were at war at the time. A. the;

问题补充：

They are having debate about whether the two countries were at war at the time.

A. the; the

B. a; the

C. the; 不填

D. a; 不填

答案：

A. the; the

B. a; the

C. the; 不填

(答案→)D. a; 不填

解析：句意：他们正在进行一场辩论，在那个时候，这两个国家是否在交战。第一个空，泛指“一次辩论”，故用不定冠词a；第二个空，be at war是固定用法，意思是交战，选D。