2. How to Improve Your English 
    
Mack is talking to his friend Don. 
    
M: Hi, Don! How are you doing in your English class? 
    D: Not so well, I'm afraid. 
    M: What's the problem? 
    D: I'm not improving. Tell me, how come your English is so good? 
    M: Well, uh…I have an American girlfriend. 
    D: Aha! That's it. Now I know what to do. (He runs off.)
    M: Hey, Come back! I was just kidding!