结构:am/ is/ are + doing ( 现在分词)
1.What are you doing?I am watching TV.
2.Is he cleaning the room now?
3.They aren't looking at the blackboard.
4.The studnets aren't runninig now.They are playing football.
5.What is your mother doing?She is cooking.
6.What is your father doing?He is reading.
7.What are they doing?They're playing basketball.
8.She isn't listening to to radio.
9.I am doing my homework now.
10.Listen.The girls are singing .