______for a long time, but he tried his best to make up for what he missed.
—Have you got an i Phone 5? —No. —You' d better buy ____.It' s really cool!
—When I first got to Harvard, my awkward English brought me great trouble. ——Oh, dear, it _______a struggle for you to keep up with other students.
—Jack, did you see my son Harry just now? —No,Mrs. White. I _______computer games.
Water, which seems so simple and common, is ______ makes life possible.
—Jimmy had a lot of parties recently. —Yes, that might ______ why he didn't do well in the test.