完形填空

　　 The computer was one of the most important inventions in our life. The first computer was as large as a room.

Now some computers are as   1    as television sets. Some computers can even be smaller than a book. About 20 years ago, the computer was a strange machine in China. Not many people   2    it and said yes to it.

         Today much of that is   3 . In 1984, when Deng Xiaoping  4   two pupils working on the computers in Shanghai, he said that computer lessons     5 start from children. So there was the first computer book for middle school students. Now in Shanghai   6    all middle schools have classrooms for computer courses(课程). Some of the students now have their   7  computers at home. With the help of the Internet, they can send and    8   messages and e-mails. They can learn about the world more quickly.

         Now people are    9    using computers in banks, factories, airports and so on. The computer is coming into everyone’s life, so it is important to learn     10  to use a computer freely.

某同学在学习浮力时感到物体上浮和下沉是受浮力大小影响的，因此他得出结论“受浮力大的物体在液体中会上浮，受浮力小的物体在液体中会下沉。”请你选取身边的器材或物品证明他的观点是错误的。