如果你想把你的姐姐介绍给你的朋友，你可以说：
A.This is my mother. B.This is my sister. C.This is my brother.
—________ you playing football?
—Yes, we ________ .
A．Are；areB．Do；doC．Is；is
—What is Miss White doing?
—______________
A．He is reading a book. B．She is writing a letter. C．I am singing.
—Is your ________ running now?
—Yes, he is.
A．brother B．sister C．mother
— ________ are they doing?
—They are playing computer games.
A．Who B．what C．What
What is the emergency number in Canada?
A．911 B．999 C．000