Выпиши слова, перед которыми можно употребить артикли (a / the)

a pen, a boy a girl, a tree. a flower, a table, a chair, a bed, a window, a door, a desk, a ball, a doll,

a plane, a plate, a bag, a book, a copy-book, a pan, a dog, a cat, a cow, a horse, a house, a leg,

the sky, the moon, the north, the south, the east, the west, the earth,