Do you know a spaceship flies at about nineteen kilometers ________ second?

The light blue jeans look cool. Could I ______?

We can’t ______ the car.There ______ something wrong with the engine.

With the world economy growing weaker, for many young people, the dream of landing a good job is becoming harder and harder ________.

Remember this: ________ careful you are, ________ mistakes you will make.— We know, Miss Gao.