—Daddy, how much do you earn an hour? —If you ______ know, $20 an hour. A. may B- must C.can D.should
Much to our disappointment, things are not going so well as _______.
I’ll never forget such a beautiful place _____ I spent my childhood there with my grandma.
—Do you know the tower ___ in the heart of the city? —Do you mean the one ___ to the north of the city library?
—Do you know ____ the 2011 Xiamen International Marathon was held? —On January 2.
Scientists across the world agree that this is an invention of ____ great significance, ____ invention that will greatly change human life.