I.

1. but

2. and

3. but

4. but

5. and

II.

1. because

2. but

3. and

4. and

5. but

6. but

7. so

8. because

IV. 

1. Câu này mình nghĩ là and đó ạ

5. but

7. so

8. because 

9. because

10. or

V. 

1. because

2. so

3. because ( câu này mk ko chắc )

4. but/because

5. and/but/so

6. but/and

7. and/because

8. but/ because

9. so

10. and/so

11. and

VI.

1. She's in hospital because she had an accident

2. They work many much but they don't have money ( câu này mình k chắc )

3. Paul asked me a question, so I replied

4. I buy tomatoes, peppers and potatoes. 

$\Rightarrow$

Ex1:

1. but

2. and

3. but

4. But

5. or

Ex2:

1. because

2. so

3. or

4. and

5. but

6. but

7. so

8. because

Ex3:

1. but $\to$ because

2. so $\to$ or

3. because $\to$ but

4. or $\to$ so

Ex4:

1. and

2. because

3. but

4. but

5. but

6. and

7. so

8. because

9. so

10. and

Ex 5:

1. because

2. so

3. and

4. but - because

5. and - but - so

6. about - and

7. and - because

8. but - because

9. so

10. but - so

11. and

Ex 5:

1. She's in the hospital because she had an accident.

2. They work many hours but they don't have much money.

3. Paul asked me a question, so I replied.

4. I buy potatoes, tomatoes, and peppers.