Rewrite the sentences

1. I bought my computer from that man (Relative ProNoun) 
----> That's the man from.......
2. If Peter (come) ......, tell him to phone me 
3. The cake made by my mother was very delicious (prep+ whom, which) 
----> The cake which............
4. My Thuan Bridge is one of the most beautiful bridges in Vietnam. Do you know it?  (prep+ whom, which) 
-----> Do you..............