—Could you tell me_______________? I’ll meet you at the airport.—At 11:00 am.
---Must I clean the floor now? ---__________. It is too dirty.
---How long may I _____________ the book? ---Two weeks.
These aren’t my keys. Mine ___________ in the drawer.
The old man is too tired _________ go any further.
His father is __________ engineer and he works __________ research.