单选题 According to a recent census, suburban residents today have become______more diverse in cultural background than they were in the 1960s.

【正确答案】 B

【答案解析】解析：应该使用副词修饰形容词比较级more diverse，因此副词(B)remarkably(显著地，不平常地)是正确答案。形容词(A)，动词和名词(C)，动词的过去分词形式(D)都不能修饰形容词比较级。