They used to make to meet and have a party at the end of a month.A. a ruleB. it a ruleC.

问题补充：

They used to make to meet and have a party at the end of a month.

A. a rule

B. it a rule

C. it rule

D. them a rule

答案：

A. a rule

(答案→)B. it a rule

C. it rule

D. them a rule

解析：考查代词。本题考查it作形式主语，真正的主语为不定式to meet and have a party at the end of a month，rule为可数名词，故选B。