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Flying kites —a popular hobby
People have been making and flying kites for about 2,000 years. No one knows for sure who invented the kite. Some historians (历史学家) believe the ancient Chinese might start the kite flying 2,000 years ago. And now it is still a popular hobby in China, Japan, Korea and other countries of the Far East where beautifully decorated kites appear in different colors. In China, there is even a special Kites Day on which children and adults fly kites. In Japan, families fly fish kites on Children's Day, May 5th.
Simple kites are made by crossing two sticks and covering them with paper or cloth. And then people put a string at the end.
Kites are made in many different sizes, colors and shapes. A flat kite is the oldest and simplest type of kite. It flies because air flows over and under the kite's wings. The pressure under the wings helps the kite lift into the air.
Today most people fly kites as a hobby. Kite festivals are organized in many parts of the world.
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两球用细线悬挂于天花板上且静止不动．两球间是一个轻质弹簧，如果突然剪断悬线，则在剪断悬线瞬间 