This is a ball.（改为一般疑问句,并作否定回答）
问题描述：
This is a ball.（改为一般疑问句,并作否定回答）
答
-Is this a ball?
-No,it isn't.
变一般疑问句很简单，一般来说就是把be动词或者助动词什么的放到前面了就行了，然后this这一类的放到后面...
否定回答用it来做代词是固定用法、基本所有的that,this,it什么的最后都用IT修饰了...
答
Is this a ball?
No, it isn't.
(No, it's not)
[No, it is not]
答
Is this a ball？
No，it isn't.
答
is this a ball?
否定回答：no, it isn't
答
Is is a ball?
No,it isn't.
答
It this a ball?
答
Is this a ball?
No, it isn't.