自行車是一種最便利最經濟的交通工具,不論城市鄉村,什麼道路都能行走。可是大家都知道自行車並不是任何人都會騎的,因爲牠只有兩個輪子,開始騎自行車總要學些日子,像小孩學走路一樣,慢慢地懂得平衡牠的方法了,才不會倒。但是我們怎樣使自行車保持平衡而不倒的,許多人就不曉得這個道理了。是不是由於輪子旋轉的緣故?因为我 Bicycles are the most convenient and economical means of transportation. No matter what the city or country is, they can walk. However, we all know that bicycles are not for everyone to ride, because they only have two wheels. It is always necessary to learn how to balance a child’s learning and how to balance it. But how do we keep the bike balanced and not fall, many people do not know this truth. Is it because of the rotation of the wheel? Because I