单选题 There was a rapid increase in population in the last century.
A. slow B. high C. shocking D. quick

【正确答案】 D
【答案解析】rapid和quick同义，意为“快的、迅速的”；slow：缓慢的、迟钝的；high：高的、昂贵的；shocking：骇人听闻的、震惊的。