______ these your _________?
–Have you ever been Canada? --__________.But I hope to go there one day!
--Would you mind opening the window? It’s too hot. --__________.
—Listen ! Helen is singing in the next room. —It __________ be Helen. She is in Tianjin now.
_________ exciting match it is! Wonderful players and wonderful teams!
Which of the following signs means you can escape from the fire?