Вставь артикли a или an в словах: pen, apple, pencil, rubber, ruler, book, orange, elefant, window, door, cat, umbrella, ball, train.

A pen
an apple
a pencil
a rubber
a book
an orange
an elephant
a window
a door
a cat
an umbrella
a ball
a train

A pen, an apple, a pencil,
a rubber, a ruler, a book, an orange, an elephant, a window, a door, a cat, an umbrella, a ball, a train