Good morning, class. Today we're going to discuss the history of the bicycle. Now, many people think the bicycle was invented in the 19th century, but its origins actually go back further. The first two-wheeled vehicle, called a 'draisine', was invented by a German baron in 1817. It had no pedals; you pushed it with your feet. Later, in the 1860s, pedals were added to the front wheel in France. However, this design was dangerous because the front wheel was very large. It wasn't until the 1880s that the 'safety bicycle' with a chain drive and two equal-sized wheels was developed in England, which became the model for modern bikes.
❓ 19世纪60年代的自行车设计存在的主要问题是什么?
A. A. 它没有踏板,因此速度很慢。
B. B. 前轮过大,导致安全隐患。
C. C. 它太重了,无法骑上坡。
D. D. 链条在使用过程中经常断裂。
✅ 正确答案
B. The front wheel was too large, causing safety issues.