Use a Relative pronoun preceded by a preposition to combine each pair of sentences below

Use a Relative pronoun preceded by a preposition to combine each pair of sentences below. 1. The teacher is Mr Pike. We studied with him last year. *Ex: the teacher with whom we studied last year is Mr Pike. 2. The problem has been discussed in class. We are very interested in it. 3. Many diseases are no longer dangerous. People died of them years ago. 4. Do you see my pen? I have just written the lesson with it. 5. I like standing at the window. I can see the park from this window. 6. We are crossing the meadow. We flew kites over it in our childhood. 7. They are repairing the tubes. Water is brought into our house through the tubes. 8. In the middle of the village there is a well. The villagers take water from this well to drink. 9. The middle-aged man is the director. My father is talking to him. 10. This is a race opportunity. You should take advantage of it to get a better job. 11. The boy is my cousin. You made fun of him. 12. This matter is of great importance. You should pay attention to it. 13. The woman lives next door to me. You gave place to her on the bus. 14. This snake is venomless. You are afraid of it. 15. The examination lasted two days. I was successful in this examination. 16. These children are orphans. She is taking care of these children. 17. The two young men safe not good persons. You are acquainted with them. 18. This is a result of our work. I'm pleased with it. 19. There is a "No Parking" sign. I do not take notice of it. 20. Mr Brown is the man. I'm responsible to him for my work. *Cái ví dụ ở trên áp dụng cho tất cả các câu ở phía dưới.