This is _____ and we must _____ on it.A hard work; work hard B a hard work; work hardC hard work; hard work D work hard; hard work
—How old is Tom?—He is ____.
—Do you have a small mouth?—No, I don’t. I have a wide ____.
—____ your sister know Lucy?—No, she ____.
—____ is your schoolbag?—It’s green.
—Is this your book, Alice?—Yes, it is ____ book.