50．A．to                          B．on                         C．of                          D．for

（A）

    Mr Sun gets off the plane．It is his first time to come to London．He has no friends here．Before taking off，he has learned much about London．But he isn’t confident（自信的）of his English．He is a little afraid．

    Now he has a problem-He can’t find his map．That means he would get lost．He wants to buy another map but he doesn’t know where to go．Just then here comes an Englishman．Mr Sun goes up to him and asks for help．

    “Excuse me．sir．I'm sorry…a map…，”says Mr Sun．

    The man looks very surprised．He says．”Sorry? I don’t understand you．”

    Mr Sun tries again，but he still can’t explain（解释）clearly what happened to him．Finally，in Chinese，he says sadly，“My God! What should I do without a map?”

    “Why don’t you buy a new one？”the young man replies in Chinese．

    Mr Sun is glad to hear this．He has a talk with the man in Chinese．The Englishman says there are many English people learning Chinese．They want to learn about China．Some of them hope to work in China in the future．