【题目】阅读下列短文,从每小题的三个选项中选出最佳选项。

【1】—Is the boy riding a bike? ( )
—
A. Yes, he is.B. No, he isn't.C. Yes, I am.
【2】Look at the three birds. They now. ( )
A. are singB. are singingC. singing
【3】—What are the dogs doing? ( )
—
A. They are sleeping. B. They are running. C. They are flying
【4】Which one is right (正确的)? ( )
A. The rabbit is eating.
B. The girl is flying a kite in the park.
C. The turtles (乌龟)are swimming in the water.