19. Russia is a country which extends across _____ .
________ at the door before you enter my room, please.
________ with care, one tin will last for six weeks.
— Can I have a day off tomorrow, Mr. Johnson? — ________. I can manage without you.
—Why not have a birthday party for our mother? —________.
—Do you know the boy ________ is sitting next to Peter? —Yes.He is Peter's friend.