Good morning, everyone. Today we're going to look at the history of the bicycle. Now, many people think the bicycle was invented in the 19th century, but actually, the first two-wheeled, pedal-less machine appeared in 1817, called the 'draisine'. It was made of wood and had no pedals; you pushed your feet against the ground to move. However, it was not until the 1860s that pedals were added, creating the 'velocipede'. The real breakthrough came in 1885 when John Kemp Starley designed the 'Rover' safety bicycle, which had a chain drive and equal-sized wheels. This design made cycling much safer and more comfortable, and it quickly became popular. So, to summarize, the key improvement in 1885 was the introduction of the chain drive, which allowed the wheels to be the same size.
❓ 강의에 따르면, 1885년에 출시된 로버 안전 자전거의 주요 장점은 무엇이었습니까?
A. 나무 바퀴를 사용하여 더 가벼웠다.
B. 체인 드라이브를 사용하여 동일한 크기의 바퀴를 장착할 수 있었다.
C. 페달이 달린 최초의 자전거였다.
D. 그것은 작은 엔진으로 작동했다.
✅ 正确答案
It used a chain drive, allowing equal-sized wheels.