People have been using the wind energy for a long， long time． More than 5，000 years ago， ancient Egyptians made boats powered by the wind． In 200 B．C．， people used windmills （风车） in China．

    Today， we collect the wind's energy with wind turbines （涡轮）． A turbine is similar to a windmill；it is a very tall tower with two or three blades （叶片） at the top． These blades are turned by the wind．The blades turn a generator （发电机） located inside the tower， which creates power．

    Groups of wind turbines are known as wind farms． Wind farms can be found near farmland，in narrow mountain passes， and even in the ocean， where there are stronger winds．Wind farms create power for nearby homes， schools and other buildings．

    In places like the Midwest and along coasts， winds can provide cheap power． Another great advantage of wind power is that it is a clean form of energy． Wind turbines do not burn oil or coal and do not pollute the air．

    Wind is not always an ideal source of energy， however． Wind speed changes from time to time， depending on the time of day， weather and location． Wind turbines can be also dangerous for bats and birds．These animals cannot always tell how fast the blades are moving and crash into them．

                                                   Title： （1）　　Energy

Ancient times	People in Egypt made wind﹣powered boats（2）　　5，000 years ago． People in China used windmills in 200 B．C．
Modern times	It is（3）　　with turbines， which are tall windmill﹣like towers with two or three blades at the top and a generator inside． The wind turns the blades and the blades tum the generator to create power．
Advantages	Winds produce power at a low（4）　　 in certain areas． Wind turbines do not cause air pollution．
Disadvantages	Wind speed does not remain at the same（5）　　all the time． Wind turbines can be dangerous for animals like bats and birds．