Bicycles Are Used Around The World

本文主要介绍自行车，自行车一开始只归男性用，但现在男性、女性和小孩都可以骑自行车。自行车大多是两轮的，但也有单轮的、三轮的、四轮的。

Bicycles are everywhere around the world. Bicycles are used by people of all ages around the world. It’s common in many cities to see thousands of bikes streaming down a street.

At first， only men rode bicycles. It was thought that only men could run machines， and that women wouldn’t be able to control a bicycle. In the 1890s， though， with women’s growing independence（獨立）， bicycles offered women a way to travel by themselves. Today， of course， men， women， and children ride bicycles.

Most bikes today have two wheels， but you’ve probably seen other kinds， too.

Some people start riding bikes that have three wheels. The third wheel makes the bike easier to balance. These bikes are called tricycles. As you’ve seen， the bi—in bicycle means“two”. The tri—in tricycle means “three”. Bikes with three wheels aren’t just for young children. They matter to adults because bikes with three wheels can help move people or things. The most common kind of adult tricycle is the rickshaw（黄包车）. Rickshaws are used as bike taxis in many parts of the world.

Some bikes also have only one wheel and no handlebars（把手）. These bikes are called unicycles. The first part of the word， uni-， means “one”. Riding a bike with only one wheel is a balancing act—that’s why unicycles are used in the circus（马戏团）.

There are also bikes with four wheels. Bikes with four wheels are called quadracycles. Again， the first part of the word refers to the number of wheels. In this case， quadra-， means “four”. what kind of bikes do you like？

紧跟训练

根据上面短文内容填空。