— I plan to go out for a bicycle trip. But I’m afraid I don’t know the .— A map is helpful, I think.
—Humans can’t live _______ air.—I agree with you.
—Who taught _______ Japanese?—I learned it by _______.
—You’d better not read _______. It’s bad for your eyes.—You’re right. I won’t do that again.
_______ necessary for us _______ English well.
—I am afraid we will miss the early bus.—Don’t worry. We have _______ time to do it.