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.
❓ 안전 자전거가 이전 디자인보다 훨씬 개선된 점은 무엇이었나요?
A. 더 큰 앞바퀴를 장착하여 속도를 높였다.
B. 앞바퀴에 페달이 포함되어 있었습니다.
C. 체인 구동 방식과 동일한 크기의 바퀴를 사용하여 안정성을 확보했습니다.
D. 페달이 없는 최초의 자전거였다.
✅ 正确答案
It used a chain drive and equal-sized wheels for stability.