1  - b  

2  - c 

3 - d 

4  - e 

5  - a 

Bài 4

1. were; would... do

Giải thích: câu DK2: If QKD , would/could V3

2. exercised; would be

Giải thích: câu DK2 

3. had; would build

Giải thích: Câu DK2 

4. tidied; wouldn’t be

Giải thích: Câu DK2

5. was/were; would grow 

Giải thích: Câu DK2

Bài 5

1. If people didn’t rubbish in the street, it would look attractive.

2. If there weren’t so many billboards in our city, people could enjoy the view.

3. If there wasn’t so much light in the city at night, we could see the stars clearly.

4. If we didn’t turn on the heater all the time, we wouldn’t have to pay three million dong for electricity a month

5. If the karaoke bar didn't make so much noise almost every night, the residents wouldn’t complain to its owner

6. She wouldn’t have a headache after work every day if she didn’t work in a noisy office.

Ex3:

1. B

2. C

3. D

4. E

5. A

Ex4:

1. Were - would you do

2. Exercise - will be

3. Had - would build

4. Tidies - will not be

5. Were - would grow

Ex5:

2. If there weren't sk many billboards in our city, people could enjoy the view

3. If there weren't so much light in the city at night, we could see the stars clearly

4. If we didn't turn on the heater all the time, we wouldn't have to pay three million dong for electricity a month

5. If the karaoke bar didn't make so much noise almost every night, the residents wouldn't complain to its owner

6. If she didn't work in a noisy office, she has a headache after work every day