I’m planning to hold a party in the open air, but I can make no guarantees because it __________ the weather.[ ]

We aren’t sure of the weather. We _______ sightseeingunless it_________ tomorrow.

The man showed us so heavy a stone ________ no man can lift.

She had to _____ from school for a week to take care of her sick mother in hospital.

23. _______ the plane have taken off on time? — I’m afraid not. The fog was too thick then.