增加：在缺词处加一个漏字符号（^），并在其下面写出该加的词。
删除：把多余的词用斜线（\）划掉。
修改：在错的词下划一横线，并在该词下面写出修改后的词。
注意：1．每处错误及其修改均仅限一词；
2．只允许修改10处，多者（从第11处起）不计分。
We all know that cycling is a greatly exercise. A doctor tells me people who lives the longest are dancers and cyclists. Maybe it is because the combination of fresh air, smooth movement and exercise. Whether you ride a bicycle, you don't use petrol. So they are not producing carbon dioxide and not cause air pollution. Just see how cars have been taken over our cities. They often run at high speeds, what may put our lives in danger. And there were traffic jams, too. Our cities will be better places if we replace cars with bicycle.
