--- Is that the small town you often refer to?
--- Right, just the one you know I used to work for years.
A. that
B. which
C. where
D. what
网友回答
A. that
B. which
(答案→)C. where
D. what
解析：此题考查的是定语从句，the one 做先行词，you know 为插入语，从句中不缺少主语或宾语，而缺少地点状语。因此选C。