сочините не большой текст,используя слова с чередованием а-о в корнях

какую общую часть пропустили в словах...ник,...а,...ной,...ок,...истый

Помогите пожалуйста если не трудно

 13. Sam really ___ to pay more attention during lessons. 
a)ought b)should c)might
14. You ___ expect me to know everything!
a)have to b)can't c)must
15. You ___ to use your mobile phone on an aeroplane.
a)aren't allowed b)can't c)don't have
16. Let's ask Eleanor - she ___ know.
a)can b)shouldn't c)might
17. I ___ see you later if I finish work on time.
a)can't b)might c)must
18. He ___ to get there before we do.
a) is bound b)must c)is able
19. ___ attend the meeting?
a) Must I b)Do I have to c)Am I
20. You ___ pay for the hotel room. Your company has already paid.
a)can't b)don't have to c)mustn't

помогите написать сочинение на тему казахский народны костюм