You (a)   perform professionaly until you have finished

school. (it's forbldden)

You (a)   wear а uniform. (it's а rule)

You (a)   choose а wide range of classes. (you're allowed)

You (a)   to work hard. (it's necessary)

You (a)   take dance classes. (lt's possible)

lt's possible it'll rain later. - It (a)   rain later.

lt's necessary to talk to the headmaster. - You (a)   to talk to the headmaster.

lt's forbidden to bring pets into the classroom! - You (a)   bring pets into the classroom!

lt isn't necessary for you to finish the project by Wednesday. - You (a)   to finish the project by Wednesday.

Always wear а uniform, it's а rule. - You (a)   always wear а uniform.

lt's a good thing to revise for a test over the weekend. - You (a)   revise for a test over the weekend.

Everybody is obliged to hand in their homework on time. - Everybody (a)   hand in their homework on time.