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 against the ground. Later, in the 1860s, pedals were added to the front wheel, but this design was unstable. By the 1880s, the 'safety bicycle' with a chain drive and two equal-sized wheels became popular, making cycling safer and more accessible. Interestingly, the bicycle's popularity grew not only for leisure but also as a means of transport for workers, especially in European cities. Now, what was a key improvement of the safety bicycle?
❓ 강의에서 언급된 안전 자전거의 주요 개선점은 무엇이었나요?
A. A. 앞바퀴에 페달이 연결되어 있었다.
B. B. 그것은 체인 구동 장치와 크기가 같은 두 개의 바퀴를 사용했다.
C. C. 그것은 이전 모델들보다 더 가볍고 빨랐다.
D. D. 페달이 전혀 필요하지 않았다.
✅ 正确答案
B. It used a chain drive and two equal-sized wheels.