1. Don’t talk about such things of __________ you are not sure.
A. which
B. what
C. as
D. those
2. Is this the factory __________ you visited the other day?
A. that
B. where
C. in which
D. the one
3. Is this factory __________ some foreign friends visited last Friday?
A. that
B. where
C. which
D. the one
4. Is this the factory __________ he worked ten years ago?
A. that
B. where
C. which
D. the one
5. The wolves hid themselves in the places __________ couldn’t be found.
A. that
B. where
C. in wh ...