In your schoolbags, you may have pencils, some kinds of pens, rulers and some books. 1 of these things grow in the fields. They were all 2 in factories. And, of course, they were 3 by some people. There have not always been pencils or pens, rulers or books. Thousands of years ago, no one 4 about these things. Even the 5 invention has the greatest technological advance at its time.

    Who invented them first? How did they have such clever 6 ? We don't always know. There have been thousands of inventions, large and small in the human history. Some of these inventions have greatly 7 the world, such as paper， printing, radios, telephones and computers, and we know the inventors. But we have forgotten most of the other inventors. 8 invented the clock, for example, or the lock to the door? We don't know.

    There have been thousands of inventors and we should be grateful to them for their clever ideas. New ideas are 9. They can change our lives. Without inventions, we would still live in forests, with nothing to wear and no ice cream to eat. Will you be one of them when you 10?