—Can I pay the bill by check?--- Sorry, sir. But it is the management rules of our hotel that payment ____ be made in cash.

--            you interrupt now? Can’t you see I’m on the phone? --Sorry sir, but it’s urgent.

--- My son is _____ to be seen. Where has he gone? --- I think he _____ in the building. 

For the safety, everyone _________ obey the traffic rules when he is driving or walking.

—Mum, I'm tired.—Well, if you ________ go to bed after midnight every night, what do you expect?