6. 1) piece
2)pair
3)piece
4)piece
5)pair
6)pieces
7)pairs
8)pair
9)pair
10)piece
а в 5 зад прочитать просто
№10 1. haven't 2. isn't 3. can't 4. I'm not 5. aren't 6. hasn't
№13 1. do 2.does 3.does 4.does 5.do 6.does 7.do 8.do 9.does 10. does 11.do 12. does 13. do 14.does
№14 1. don't 2. doesn't 3. doesn't 4. don't 5.doesn't 6.doesn't 7. don't 8. doesn't 9. don't 10. don't 11, doesn't 12. doesn't 13. don't 14. don't
Если существительное в единственном числе, то is,а если во множественном, то are!
Если я правильно понимаю, надо привести их в изначальную форму:
Being, becoming, ???, ???, bleeding, braking, building, burning
(Прости если неверно, с begam и bit я не поняла)