1. I can never forget the day on which(on which/in which) we worked together .
2. Last summer we visited the West Lake, for which(for which/for that) Hangzhou is famous in the world.
3. This is the reason for which(with which /for which) he didn’t come to the meeting.
4. The engineer with whom(with who/with whom) my father works is about 50 years old.
5. The pen with which(with which /by which) he is writing is mine.
6. Can you lend me the book about which(about which/with which ) you talked the other day?
7. This machine which I have looked after(after which I have looked /which I have looked after) for many years is still working perfectly.
8. That is not the way in which(in which/with which) I do it.
9. This is the magazine from which(which/from which) I copied the paragraph.
10. That is the day which(which/on which) I’ll never forget.
