Ex3:
2. A: Were you at home at four o'clock ?
    B: Yes, I was
3. A: Was that book interesting?
    B: Yes, it was
4. A: Were they late for school yesterday ?
    B: No, they weren't
5. A: Was your father at work at five o'clock?
    B: Yes, he was
6. A: Was your sister with you at the cinema?
    B: No, she wasn't
7. A: Were you and Ken in London last month?
    B: Yes, we were
8. A: Was Tina's dress nice?
    B: No, it wasn't

Ex5: 
1. We weren't tired
2. There was a mouse in the kitchen !
3. Peter and Jane were at home
4. Why was she sad?
5. The film wasn't very interesting
6. Were there any e-mails for me?
7. There weren't busy
8. There was some lemonade in the fridge. 
Chúc e học tốt, c chỉ giúp đc e 2 bài này thôi nhé