Your grandpa had lived here for 50 years before he moved to London, _____?       [ ]

A. was it            

B. did he        

C. had he        

D. hadn't he

用SQL语言描述“在教师表中查找男教师的全部信息”，以下描述正确的是（ ）。

A．SELECT FROM 教师表IF(性别=‘男’)

B．SELECT性别FROM教师表IF(性别=‘男’)

C．SELECT * FROM教师表WHERE(性别=‘男’)

D．SELECT * FROM性别WHERE(性别=‘男’)