7．
阅读短文,从每小题的三个选项中选出最佳选项。
Orville Wright and Wilbur Wright are brothers. Their job is to mend bicycles. In their spare time, they like inventing things. One day, they are watching some birds flying in the sky .They want to fly in the sky, too. They think they should invent a flying machine, so they can fly in the sky too. But it's a hard work to invent a flying machine. They work very hard. First, they watch how the birds fly. Next, they draw a picture of a flying machine. Then they build the machine, it is heavy and ugly, the machine can't fly to the sky. So they work again and make it lighter. Finally, they make the first plane in the world, though the plane only flies in the sky for twelve seconds.
