单选题 Only after ______ requests by the tenants did the super-intendant do something about the broken intercoms in some of the apartments.
A. repeat B. repeated
C. repeating D. repetition

【正确答案】 B
【答案解析】[解析] 横线处所填单词修饰名词requests。过去分词(B)repeated和现在分词(C)requirements都可作形容词。被修饰的名词和分词之间如果是被动关系，就用过去分词，如果是主动关系就用现在分词，request和repeat是被动关系，故选B。