Bài 1:

1. since

2. for

3. for

4. for

5. for

6. for

7. since

8. for

9. for

10. for

Bài 2:

1. for

2. for

3. for

4. for

5. since

6. for

7. for

8. for

9. since

10. for

Bài 3:

1. played

2. cleaning

3. had

4. read

5. met

6. visit

7. has bought

8. forgot

9. Did - win

10. eaten

Ex1:

1. since

2. for

3. for

4. since

5. for

6. for

7. since

8. since

9. since

10. for
Ex2:

1. for

2. for

3. since

4. for

5. since

6. for

7. for

8. for

9. since

10. for

Ex3:

1. played

2. have cleaned

3. were

4. have read

5. met

6. have never visited

7. bought

8. forgot

9. did - win

10. haven't eaten