You ought to have put the milk in the refrigerator, and now ________sour.
Can you tell me ______?
Did you see him yesterday?—No, when I got to the airport, he a taxi for home.
The boy is good at playing _____ guitar and _____ table tennis.
Tell the kid to ________ the fireworks(烟花、爆竹),please.——Yes, you are right.