We are now going to look at the history of the bicycle. The first bicycle, invented in the early 19th century, had no pedals; riders pushed their feet against the ground to move forward. Later, in the 1860s, pedals were added to the front wheel, but this design was unstable and difficult to ride. It wasn't until the 1880s that the 'safety bicycle' appeared, featuring two equal-sized wheels and a chain drive to the rear wheel. This design made cycling much safer and more comfortable, and it quickly became popular among both men and women. Today, the basic design of the safety bicycle remains largely unchanged.
❓ 19世纪80年代推出的“安全自行车”的关键改进是什么?
A. 它有一个更大的前轮,以便实现更快的速度。
B. 它在前轮上安装了踏板。
C. 它有两个大小相同的轮子,并通过链条传动驱动后轮。
D. 它更轻便,且可折叠以便于存放。
✅ 正确答案
It had two equal-sized wheels and a chain drive to the rear wheel.