All over the city, history and modernity come together to make _______ an essential place for tourists to discover.
—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.
—The weather isn't good enough for an outing, is it?—Not in the least. We can't have ______ at this time of the year.