This is a pen.

This is a notebook.

This is a book.

This is a three-ring binder.

This is a notebook.

This is a book.

These are notebook.

These are three-ring binders.

These are books.

This is a book.

This is a dictionary.

This is a notebook.

This is a desk.

This is a chalk.

This is a computer.

This is a desk.

This is a chalk.

This is a computer.

These are desks.

These are chalks.

These are computers.

This is an eraser.

This is a backpack.

This is a board.

This is an eraser.

This is a folder.

This is a board.

This is an eraser.

This is a backpack.

This is a cellphone.

This is an eraser.

This is a folder.

This is a board.

This is an eraser.

This is a backpack.

This is a cellphone.

This is a notebook.

This is a piece of paper.

This is a marker.

This is a notebook.

This is a piece of paper.

This is a marker.

This is a board.

This is a CD.

This is a chair.

This is a board.

This is a CD.

This is a chair.