There is a police car _____ the bus. The police are watching the traffic.
— You look happy today.— Yes, the news says the poor children can go to school again ______ the help of ProjectHope.
— Where are your parents? — They ____ Shanghai. They will be back in two days.
— Do you know Mozart? — Of course. He wrote _____ of beautiful pieces of music.
— I went to your house yesterday afternoon, but you were not in.— Sorry. I _______ basketball with my classmates.
—________you _____your homework yet? —Yes, I ___it ten minutes ago.