Respuesta :

this:
This is an apple 
This is a bus
This is a table.

that:
That is a book
That is a pencil
That is a dog.

those:
those are dolls
Those are umbrellas
Those are cars.

these:
These are dogs
These are letters
These are schools.

recuerda singulares y plurales marcando la diferencia.
espero que te sirva.