17 谁在擦窗子? (2分钟)

LESSON SEVENTEEN?

Who is cleaning the window??
Who is cleaning the door??
Who is cleaning the blackboard??
Who is sweeping the floor???

I am cleaning the window.?
You are cleaning the door.?
He is cleaning the blackboard.?
She is sweeping the floor.

??

Translation(译文)
谁在擦窗子??
谁在擦门??
谁在擦黑板??
谁在扫地板??

?

我在擦窗子。?
你在擦门。?
他在擦黑板。?
她在扫地板。

who谁 

cleaning 擦

 window窗户?
 door门
blackboard黑板
 sweeping打扫

floor地板?