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.
❓ 安全自転車が初期の設計よりも大幅な改良となった理由は何でしょうか？
A. 速度を出すために、前輪が大きくなっていた。
B. 前輪にペダルが付いていた。
C. チェーン駆動と等しいサイズの車輪を使用して、安定性を確保していました。
D. ペダルのない最初の自転車でした。
✅ 正确答案
It used a chain drive and equal-sized wheels for stability.