I am going to the ______ to send a letter to my pen friend this morning.
— How many are there in the USA? — There are fifty.
— What do you want to be when you ? — An astronaut.
The dog took a piece of meat and .
All of us should our teachers as well as our parents.
— Why are you so ? — Because our ping-pong player Wang Liqin has won the world championship.