Good morning, everyone. Today we're going to discuss the history of the bicycle. Now, you might think the bicycle was invented in the 19th century, and you'd be right. However, the first two-wheeled vehicle, called a 'draisine', appeared in 1817. It had no pedals; riders pushed their feet against the ground to move. Then, in the 1860s, pedals were added to the front wheel. But this design was unstable because the front wheel was small. It wasn't until 1885 that the 'safety bicycle' was introduced, with a chain drive and two equal-sized wheels, which made riding much safer and more efficient.
❓ 1860年代の自転車デザインにおける大きな問題は何でしたか？
A. A) ペダルがまったくありませんでした。
B. B) 前輪が小さすぎて、不安定だった。
C. C) チェーンドライブが頻繁に故障した。
D. D) 二つの車輪の大きさが異なっていたため、事故を引き起こした。
✅ 正确答案
B) The front wheel was too small, making it unstable.