（C）

   ①More and more people like bicyclingand it is no surprise. It is fun, healthy and good for the environment. Maybe that's why there are 1.4 billion bicycles and only 400 million cars on roads worldwide today. Bikes can take you almost anywhere, and there is no oil cost!

    Get on a bicycle and ride around your neighbourhood. You may discover something new all around you. Stopping and getting off a bike is easier than stopping and getting out of your car. You can bike to work and benefit(受益) from the enjoyable exercise without polluting the environment. You don't even have to ride all the way.

    ②Folding(折叠) bikes work well for people when they ride the train. Just fold the bike and take it with you. You can do the same on an airplane. A folding bike can be packed in a suitcase. You can also take a common bike with you when you fly. But be sure to look for information by getting on airline websites. ③Not all airlines（航空公司） are bicycle-friendly to travelers.

    Health benefits of bicycling:

    It helps to prevent heart disease.

    Bicycling helps to control your weight.

    A 15-minute bike ride to and from work three times a week burns off five kilos of fat in a year.

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    Exercise like bicycling has been shown to make people feel better, more relaxed and self-confident.