– Is this the factoryyou visited last year?–Yes it is.A. whereB. whenC. whichD. who

问题补充：

– Is this the factoryyou visited last year?

–Yes,it is.

A. where

B. when

C. which

D. who

答案：

A. where

B. when

(答案→)C. which

D. who

解析：本句中先行词the factory为下文定语从句的逻辑宾语，指物，故引导词应用that或者which，结合所给选项，可知选C。