________ a pen.
This is a pen.
________ an apple.
That is an apple.
________ a pen.
That is a pen.
______ a cat.
That is a cat.
_______ a bag.
That is a bag.
________ a ball.
That is a ball.
________ a ball.
This is a ball.
_______ a book.
That is a book.
________ a cat.
This is a cat.
_______ a book.
This is a book.
_______ a rubber.
This is a rubber.
_______ a bag.
This is a bag.
________ an apple.
This is an apple.