Our classroom is a little untidy. Please the desks and chairs.
Don’t give up _____ you will never succeed.
Trees can stop the sand _____ towards the rich farmland in the south.
—Can’t you stop making so much noise? I really can’t _____ it.—I’m terribly sorry for giving you so much trouble.
He said that he _____ to Canada a few years ago.
—We really shouldn’t use plastic bags any more when shopping.—_____ It’s important to protect our environment.