Today we're going to discuss the history of the bicycle. In the early 19th century, the first two-wheeled vehicle, called a 'draisine', was invented by Karl von Drais. It had no pedals; riders pushed their feet against the ground to move. Later, in the 1860s, pedals were added to the front wheel, creating the 'velocipede'. However, this design was uncomfortable due to its rigid frame. By the 1880s, the 'safety bicycle' with a chain drive and equal-sized wheels became popular, making cycling safer and more accessible. This design is essentially what we still use today.
❓ “安全自行车”相比早期设计的主要改进是什么？
A. A. 它的前轮上装有踏板。
B. B. 它采用了链传动和等尺寸车轮，以提高稳定性。
C. C. 它更轻，因为它是用木头做的。
D. D. 它要求骑手用脚蹬地前行。
✅ 正确答案
B. It used a chain drive and equal-sized wheels for better stability.