问题补充：
Is this factorysome foreign friends visited last Friday?
A. that
B. where
C. which
D. the one
答案：
A. that
B. where
C. which
(答案→)D. the one
解析：考查句子结构和定语从句。The one在句中做表语，且是定语从句的先行词。The one指代this factory在句子做表语，且the one后面省略了关系代词that，that指代the one在句中做visit的宾语。故D正确。
