根据句意，用适当的短语填空。

be supposed to, be expected to, be important to

When you get on the train, it __________ bring your ID card.
You ___________ wash hands before you have meals.
Students __________ get their dream job in the future..
If you visit Heilongjiang during the winter, it ___________ take warm clothes.
You ____________ knock at the door before you go into the office.