英语试卷）
Corruption is _______ problem in countries across the world, with developing countries often believed to be more serious, although there is no evidence to suggest this is _______case.

A．a; the

B．the; a

C．不填; the

D．a; a

科目 英语   题型 单选题   难度 中等

知识点： 冠词的用法辨析