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.
❓ 1860년대 자전거 디자인의 주요 문제점은 무엇이었나요?
A. A) 페달이 전혀 없었습니다.
B. B) 앞바퀴가 너무 작아서 불안정했다.
C. C) 체인 드라이브가 자주 고장났다.
D. D) 두 바퀴의 크기가 달라서 사고가 발생했다.
✅ 正确答案
B) The front wheel was too small, making it unstable.