How do you get from here to there？Like most people, you probably drive cars or take buses. The engines of most of the cars burn gasoline(汽油). To save gasoline, as well as to reduce air pollution, some car companies have begun to produce hybrid cars, which run both on gasoline and electricity.
Hybrid cars are different from traditional cars. Traditional cars have large engines to deal with driving uphill and accelerate(加速), while hybrid cars have a small standard engine and a battery electric motor to provide electric power. Another difference is the braking(刹车)system. The electric motor is used to slow down the car instead of traditional brakes. When the car brakes, the motor produces electricity energy which is stored in the battery by itself. In traditional cars, the energy is wasted when braking. Also, in hybrid cars, the gasoline engine turns itself off when not needed. For example, when the car stops at a traffic light, the gasoline engine stops. It restarts when the driver steps on the gas pedal. (1) Hybrid cars consume less gas per mile and release less pollution than cars run on gasoline alone. (2) In general, hybrid cars have less power for climbing hills and less acceleration than cars with large engines. (3) In addition, the large batteries could be an environmental problem if they end up in a landfill(垃圾填埋地). (4) In this way, drivers must make careful decisions in buying any car.
