短文选词填空。（选择最恰当的词填在横线上，每空一词）

（orange, go, yellow, in , on, rulers, a, an, road, rules, boat, three, there, are, green , stop, )

     You must know the traffic ______ if you walk ____ a city. There ___always _____ lights for the traffic lights. You can cross the street at a ______ light and you must ____  at a red light. The _____ light means “Wait’ . If you drive ___ car, you must drive ___ the right side of the _____.