1. Yes, I do./ No. I don't.
2. Yes. I can./ No. I can't.
3. Yes, I do./ No, I don't.
4. Yes, I did./ No, I didn't.
5. Yes, they are./ No, they aren't.
6. Yes, I was./ No, I wasn't.
7. Yes, they would./ No, they wouldn't.
Седьмое предложение у вас неправильно. Правильно: All your friends would like to visit Britain, wouldn't they?