Good morning. Today we're going to discuss the history of the bicycle. The first bicycle, invented in the early 19th century, had no pedals; riders pushed their feet along the ground. By the 1860s, pedals were added to the front wheel, but this design was unstable. It wasn't until the 1880s that the 'safety bicycle' with two equal-sized wheels and a chain drive became popular, making cycling safer and more accessible to the general public. This design remains largely unchanged today.
❓ 是什么让安全自行车相较于早期设计有了显著改进？
A. 它有一个更大的前轮以提高速度。
B. 它在前轮上装有踏板。
C. 它采用了链传动和等大的轮子以保持稳定性。
D. 这是第一辆没有脚踏板的自行车。
✅ 正确答案
It used a chain drive and equal-sized wheels for stability.