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. By the 1860s, pedals were added to the front wheel, but this design was unstable. In 1885, the 'safety bicycle' appeared with a chain drive and two equal-sized wheels, making it much safer. Interestingly, the popularity of bicycles led to better road surfaces and even influenced the design of early automobiles. However, it wasn't until the 20th century that bicycles became affordable for the general public.
❓ 안전 자전거가 초기 디자인보다 더 안전했던 이유는 무엇인가요?
A. A. 페달이 없었고 발로 밀었다.
B. B. 그것은 체인 구동 장치와 크기가 같은 두 개의 바퀴를 가지고 있었다.
C. C. 더 큰 앞바퀴를 가져 안정성을 높였다.
D. D. 더 가벼운 재료로 만들어졌다.
✅ 正确答案
B. It had a chain drive and two equal-sized wheels.