Good morning, everyone. Today we're going to discuss the history of the bicycle. Now, many people believe the bicycle was invented in the 19th century, but in fact, early prototypes appeared as far back as the 15th century. However, the first practical two-wheeled vehicle, called the 'draisine', was created by a German baron in 1817. It had no pedals; riders pushed their feet along the ground. The major breakthrough came in 1860s in France, when pedals were added to the front wheel. But this design was unstable because of the large front wheel. It wasn't until the 1880s that the 'safety bicycle' with a chain drive and equal-sized wheels became popular, making cycling much safer and more accessible to the general public.
❓ 前轮装有踏板的白行车主要问题是什么?
A. A. 它们太重了,无法骑车上坡。
B. B. 它们因前轮过大而不稳定。
C. C. 由于链传动,它们难以操控。
D. D. 他们要求骑手用脚在地面上推动前进。
✅ 正确答案
B. They were unstable due to the large front wheel.