--Where did you see him for the first time?-- It was in the factory we worked.A. thatB. w

问题补充：

--Where did you see him for the first time?

-- It was in the factory we worked.

A. that

B. where

C. which

D. when

答案：

A. that

(答案→)B. where

C. which

D. when

解析：修饰名词factory是一个定语从句，先行词表示地点可用关系词where，故本题选B。