Have you ever heard the old saying ,"Never judge a book by its cover" ?This is a good rule to follow when trying to judge the intelligence of others. Some people have minds that shine only in certain situations. A young people with an unusual gift in writing may find himself speechless in the presence of a pretty girl when he speaks. He may not be able to find the right words. But don't make mistake of thinking him stupid, with a pen and a paper, he can express himself better than anybody . Other people may fool you into overestimating   their intelligence by putting up a good front. A student who listens attentively and takes notes in class is sure to make a favorable impression on his teachers. But when it comes to exams, he may score near the bottom of the class . It all boils down to this: you can't judge someone by appearance. The only way to determine a person's intelligence is to get to know him. Then you can see how he reacts to different situations. The more situation you see, the better your judgment is likely to be. So take your time. Don't judge a book by its cover . The writer of this passage wants to tell us    _   .
not to judge a book by the cover not to make the mistake of thinking a young man stupid not to overestimate a student's intelligence not to judge person's intelligence by his appearance