The Great Wall of China is ______wall in the world.
Have you ever read books ______ by Lu Xun?
—It’s too late. I have to go now.—Oh, it’s raining outside. Don’t leave ______ it stops.
—Thank you for the nice birthday present.—______ .
There are ______ floors in the building and my home is on the ______ floor.
— Do you know anything about Chinese knots (中国结)?— Yes. They are usually regarded ______symbols of good luck.