— _______ these her hats?—No, they _______.A.Is; isn’t B. Are; aren’t C. Are; is
We don’t know how to prevent the flu. Shall we ask Doctor Wang Hai for______?
—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.