The history of bikes

文章大意

这篇雅思听力Part4介绍“自行车两百年”展览，讲述19世纪以来自行车的发展：从无脚踏、木轮包金属的早期两轮车，到金属车架、链条与齿轮系统，再到橡胶轮胎的出现，并提到自行车因城市扩张而兴起、比马匹便宜等背景。

题目与答案

1. | Years/Time | Feature | Advantage | Disadvantage |

   | --- | --- | --- | --- |

   | 1830s | wooden wheels covered with metal | need 31_____ than walking | quite 32_____ |

   | 33_____ | Chain and sprocket are 34_____ | easier and 35_____ ride | Harder to balance |

   | 1880s | use 36_____ | more comfortable | the faster you go, the more you feel every bump |

   | 1890s | equal-sized wheels | 37_____ | dangerous before brakes appeared |

   答案：less effort|||uncomfortable|||1860s|||connected|||more smoothly|||rubber wheels|||safer

   原文定位：The early bike let people travel with less effort than walking;So the downside was that the ride was quite uncomfortable on most roads;By the eighteen sixties, though, improvements were being made;The biggest improvement;was the development of the chain and sprocket system. They’re connected;you could ride a lot more smoothly and with very little effort;By the eighteen eighties, another big change was the use of rubber wheels;This meant that bikes became a great deal safer

2. 38-40 The invention of different gears on a bicycle affected which THREE of the following?
   • wheel size
   • balance
   • rate of speed
   • the back wheel
   • safety
   • downhill travel

   答案：rate of speed,the back wheel,downhill travel

   原文定位：Changing gears is what makes those fast speeds possible. You can shift gears depending on the terrain;You can put it on a higher gear for downhill and a lower gear for uphill travel;This gear-shifting mechanism is attached to the back wheel