把This is a pencil.改为一般疑问句和否定句

问题描述:

把This is a pencil.改为一般疑问句和否定句

Is this a pencil?
This is not a pencil.

Is this a pencil?
No. This isn't a pencil.

Is this a pencil?
This isn't a pencil.

Is this a pencil?
What is this?

Is this a pencil?
This is not a pencil.