If you go by car, by bike or on foot, you must know the ________ .
A. traffic lights B. traffic C. traffic light
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.
如果你想问别人“这位是谁？” 你可以说：
A.Who is this？B.Who is that？C.Who are you？
如果你想向别人介绍你的爸爸，你可以说：
A.This is my grandpa.B.This is my brother C.This is my father
——she your friend？
——Yes，she is.
A.AmB.IsC.Are
is the girl？
A.Who B.WhatC.Whose