A/
1. didn't it?
2. won't you? (avec un léger doute pour cette réponse)
3. shall we?
4. does she?
B/
1. mustn't
2. don't have to
3. must
4. had to
C/
1. Football is well played by John.
2. Great exercices were well made by Peter.
3. Many rivers have been polluted by factories.