Is this factory you visited last week?A. thatB. whereC. the oneD. in which

问题补充：

Is this factory you visited last week?

A. that

B. where

C. the one

D. in which

答案：

A. that

B. where

(答案→)C. the one

D. in which

解析：句意：这个工厂是你上周参观的那个吗？you visited是省略先行词的定语从句，句中缺少先行词，因此用the one代替factory，做先行词。故选C。