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阅读理解
Beijing(Dec．15)－China is going green．In order to reduce air pollution and oil shortages, carmakers have announced their plans to develop hybrid vehicles(混合燃料汽车)for the Chinese market．
The first China made Toyota’s hybrid car Prius hit the road last week．Let’s have a look at the new car．
Any vehicle is a hybrid when it combines two or more sources of power．Hybrid cars use an electric motor with rechargeable batteries(充电电池)and a gasoline engine．
A hybrid car has a smaller than traditional gasoline engine and an electric motor．The gasoline engine provides 99 per cent of the power when the car is cruising(匀速行车)．
The electric motor provides extra power for running up hills or when extra acceleration(加速度)is needed．
Step into a Prius, and turn on the power．The first thing you notice is that it is quieter than a traditional car．At this point, the car’s gasoline engine is dormant．The electric motor will provide power until the car reaches about 24km/h．If you stay at low speed, you are effectively driving an electric car, with no gasoline being used, and no exhaust gas given off．
An onboard computer decides when to use the gasoline engine, when to go electric, and when to use a combination of the two．If you go over 24km/h, when you step on the gas pedal(油门)，you are telling the computer how fast you want to go．
The electric motor recharges automatically when braking．And when driving at certain speeds, the gasoline engine not only powers the car but also recharges the batteries．
When you use the brake, the electric motor acts like a generator(发电机)to produce electricity to recharge the batteries．Batteries will last for around 200,000 miles．
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