—The spacecraft has never been to the moon, ________ ?—Certainly.
—Do you often take exercise for an hour every day?—Yeah, doing that can build me up.
You'd better learn the new rules by heart.
—Maybe they have decided to trek through the jungle.—Well, I really don’t think it’s a good idea.
—The old man lives alone but he doesn’t feel lonely.—Sometimes he goes to town to see his son..
I ________ let him know it as soon as he ________ back.