单选题 The number of teachers in our college ______ greatly increased last term. A number of teachers in this school ______ from the countryside.
A) was; is B) was; are C) were; are D) were; is

【正确答案】 B

【答案解析】“the number of+名词”做主语，谓语动词常用单数形式。“a number of+名词”做主语，谓语动词常用复数形式。