Farmers grow crops either to ____their family ___to sell.
| A．feed; and | B．feed; or | C．supply; or | D．supply; nor |
---- Has Sam finished his homework today?
---- I have no idea. He ________ it this morning.
| A．did | B．has done | C．was doing | D．had done |
In ________ most countries, a university degree can give you _________ flying start in life.
| A．the; a | B．the ; / | C．/ ; / | D．/; a |
It is the first time that Martin has been to the South Pole, ________?
| A．isn’t he | B．hasn’t he | C．isn’t it | D．hasn’t it |
If it _____ for the heavy rain then, we would have arrived here ahead of time.
| A．shouldn’t be | B．weren’t | C．had not been | D．be not |
We should protect the environment, for plenty of fresh air ________ to good health.
| A．adjust | B．contributes | C．distributes | D．appeals |