無論休閑，娛樂、上學、工作，自行車都是人們最喜愛的交通方式之一。因為自行車相對而言有很多優(yōu)點，例如方便、便宜、易停放、節(jié)約能源、沒有污染而且可以強壯身體等。很多中學生也愛騎自行車上學，但騎自行車也有一定的風險，所以中學生騎自行車時要遵守一定的交通規(guī)則，注意安全。
請根據(jù)以上提示，寫一篇短文，談?wù)勻T自行車的優(yōu)點以及怎樣保證騎自行車時的交通安全。
要求：（1）不可逐句翻譯，卷面整潔，內(nèi)容通順；
（2）90詞左右，文章開頭已給山，不計入字數(shù)；
（3）提示詞，convenient（方便）
    The bicycle is one of the most popular vehicles in the word.Why are they so popular？
____________________________

【考點】交通．

【答案】The bicycle is one of the most important vehicles in the world.It has many advantages.It's cheap and easy to park bicycles.Bicycle riding can help us save energy and it is good for the environment because bicycle doesn't cause air pollution.Bicycle riding is also good exercise.It helps people become fit and makes the riders' hearts and lungs strong.
Bicycle is becoming more and more popular with the students，but every year many students get hurt in bicycle accidents.So first of all，we should obey the traffic rules.jye.ai we ride a bicycle，we should wear a helmet.If we ride a bicycle at night，we'd better wear light-colored clothes or have lights on our bicycle.It's good to learn more about  traffic signals and first aid.If we follow these suggestions，we will be safer.