They are playing football一般疑问句
问题描述：
They are playing football一般疑问句
还有：
I think it is cat。改为否定句
The cat is on the box 对On the box 提问
Is she going to school today？做否定回答
答
Are they playing football?
补充：
I don't think it is a cat.
Where is the cat?
No,she isn't.