Obligation - present and past

(1)You smoke in the library
(2)I missed my train and to wait an hour for the next one
(3) Students allowed take dictionary into an exam
(4) When I a young child I stay out late
(5) You vote Britain until you 18
(6)It’s free to get in - you have pay
(7) In a hospital you be quiet
(8) When I was child I have work
(9) You aren't to drive car in Britain until you 17
(10) Guests have breakfast any time between 8 and 9 am
(11)I remember to post this letter - it's important
(12) At College students don't to wear uniform
(13) When I was school I wear my own clothes
(14) When children to leave school your country?
(15) You allowed pay using credit card
(16) There were only 2 people in front of me in the queue so I have wait long
(17) Monday’s a holiday so we don't to go school until Tuesday
(18) Are you to take a calculator into the exam?
(19) When I at school I to do what the teacher told me
(20) When I was child I allowed eat any sweets