—Why don’t you wear your jogging shorts, mum?—Well, my legs are too skinny, if you ______ know. 

— May I take the magazine out of the reading room?— No, you can’t. You ______ read it here. It’s the rule.

He ________ sleep, although he tried to, when he got on such a hunt for an idea until he had caught it.

— Dad, must we wait until the light becomes green? — Yes, I’m afraid we ______. That’s the traffic rule.

— Could you give me a ride to the railway station? I’m going to be late.— I’ll take the nearest route. You ________ be in time for the train.