We feel our duty to make our country a better place.

How long __________ your parents ___________? —For about twenty years.

Don’t forget to take your bag when you _______ the bus.―OK, I won’t.

Don’t______, my children！Keep trying and your dream will come true.–Thank you, Miss Fang. We will do our best.

A moment, please．I’m checking if Mr. Smith _________ free tomorrow．