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。