1. They are doing housework .(分别改成一般疑问句和否定句)
疑：Are they doing housework?
否：They aren't doing housework.
2．The students are cleaning the classroom . ( 改一般疑问句并作肯定和否定回答)
疑：Are the students cleaning the classroom?
否：The students aren't cleaning the classroom.
3．I’m playing the football in the playground .(对划线部分进行提问)
①划主语I： Who is playing the football in the playground?
②划playing the football ：What am I doing in the playground?
③划the football：What am I playing in the playground?
④划in the playground：Where am I playing the football ?
4．Tom is reading books in his study . (对划线部分进行提问)
①划Tom：Who is reading books in his study ?
②划reading books：What is Tom doing in his study ?
③划books：What is Tom reading in his study ?
我把可以划的地方都写出来了,希望可以帮到你.