1)What time do we __ ( should/have to)be at the railway station?
2)I __( may not/ can't) with this film . It's too boring .
3)We've got a dishwasher , so you __ ( couldn't / needn't ) wash up
4)You look very pale, I think you __ (need/should) stay at home.
5) __(Could/might) you, please , pass me the salt.
6)He__(can't /couldn't ) open the window at it was stuck