Here are the completed sentences:

1. Mr. Tuan has a daughter, Linh. **(Linh’s)**
- Linh is Mr. Tuan's daughter.

2. I spent 5 days writing the report. **(It)**
- It took me 5 days to write the report.

3. The cup is on the book. **(under)**
- The book is under the cup.

4. There are two chairs in front of the fridge. **(behind)**
- The fridge is behind two chairs.

5. Who looks after your younger sister? **(care)**
- Who takes care of your younger sister?

6. Linda likes playing volleyball. **(Linda's)**
- Volleyball is Linda’s favorite sport.

7. Despite his old age, he runs around the park every morning. **(Even though)**
- Even though he is old, he runs around the park every morning.

8. Whose hats are those? **(Who)**
- Who do those hats belong to?

9. My school isn’t near my house. **(far)**
- My school is far from my house.

10. He went to the countryside last week, didn’t he? **(Did)**
- Did he go to the countryside last week?