You won’t catch what he said _____ you listen carefully.A. if B. after C. Unless
It’s _____ hard problem for the twins that ____ of them can work it out.
You ______ to the party if you’re so busy.
—_____I use your dictionary, Tom?—Of course, you _______
Simon improved his way of study. ________, he has made great progress.
—What color is _______ orange?—It's____ orange.