What is this?
It is a pen.
What is this?
It is a book.
What are these?
They are pencils.
What are these?
They are books.
What is this?
It is a rubber.
What is this?
It is a ruler.
What is this?
It is a pencil.
What are these?
They are pens.
What are these?
They are rubbers.
What are these?
They are rulers.