Use a Relative Adverb to combine each pair of the sentences below

IV. Use a Relative Adverb to combine each pair of the sentences below.
1. This is the house. We often stay in this house in the summer.
2. That was the time. He managed the enterprise at that time.
3. I’ll show you the second-hand bookshop. You can find valuable books in this shop.
4. I never forget the park. We met each other for the first time at this park.
5. The police want to know the hotel Mr Bush stayed at this hotel two weeks ago.
6. The reasons are basic grammatical ones. I’m scolded by the teacher for these reasons.
7. She doesn’t want to speak to the cause. She divorced her husband for this cause.
8. The road is shaded with trees. I go to school on this road every day.
9. I have not decided the day. I’ll go to London on that day.
10. He doesn’t want to sell the house. He was born in this house.
11. The airport is the most modern one. We are going to arrive at this airport.
12. He was born on the day. His father was away on that day.
13. The days were the saddest ones. I lived far from home on those days.
14. I do not know the reason. She left school for it
15. The bed has no mattress. I sleep on this bed.
16. Our school has a good laboratory. The students practise chemistry in the laboratory.
17. You didn’t tell us the reason. We had to cut down our daily expenses for that reason.
18. The book is a telephone directory. We can look up telephone numbers in this book.
19. Mrs Brown rang Dr Brown. He was going to carry out an urgent operation at that moment.
20. This is the house. We have lived there for 5 years