=>
Ex2/
1. winning -> to win
2. sits -> sitting
3. about who -> about whom
4. are searching -> bỏ are
5. from -> by
6. who -> who was/bỏ who
7. bringing up -> brought up
8. who -> whom

Ex3/
1. The woman being a writer has written several pages on this subject.
2. Customers complaining about the service should see the manager.
3. The number of students having been counted is quite high.
4. The boy would be happier if he had someone to play with.
5. The vegetables sold in this shop are grown without chemicals.
6. The first thing to remember is that we don't have enough money to carry out the project.
7. I live in a house built a century ago.
8. The people working here are very interesting.
9. I want to meet the woman teaching me how to drive.
10. The cake made by my mother was very delicious.