【题目】Experts warn that global warming will cause extreme climate changes including more______ floods, heat waves and droughts.
A. usual B. ordinary C. frequent D. common
在线课程【答案】C
【解析】考查形容词辨析A. usual通常；B. ordinary平常的；C. frequent频繁；D. common 普通的；句意：专家警告说，全球变暖导致气候的变化包括频繁的洪灾，热浪和干旱。根据句意选C项。