完形填空

　　Almost everyone uses it．There is one on my desk now．It is useful．Is there one on your desk, too? 　　1　　 am I talking about? Can you 　　2　　 what it is? It is a pencil．

　　Most pencils are about 18 centimetres long．One pencil can draw a line thirty-five miles long, or write 45,000 　　3　　! One pencil may be sharpened(削尖)　　4　　 times or more before it is too short to use, yet we can buy one for the price of an orange! I think that pencils are very 　　5　　．

　　Pencils are made in many different 　　6　　, but most people like yellow ones．There are more yellow pencils than any other color．No one knows why people like yellow pencils but they do．Someone once made a lot of pencils．Half were yellow and half were green．A man bought them and 　　7　　 them for a long time．Then he went to the market with them and said, “The green pencils, I’m sorry to say, are 　　8　　 good．They break easily．They are hard to sharpen．They don’t write well．I don’t 　　9　　 any more green pencils．I want yellow ones in the future, please．”

　　But the pencils were 　　10　　．The only difference was the color!