Good morning, class. Today we're going to discuss the history of the bicycle. The first bicycle, invented in the early 19th century, had no pedals and was propelled by the rider's feet pushing against the ground. It was called a 'hobby horse.' Later, in the 1860s, pedals were added to the front wheel, creating the 'velocipede.' However, this design was uncomfortable due to its rigid frame. It wasn't until the 1880s that the 'safety bicycle' with a chain drive and two equal-sized wheels became popular, making cycling much safer and more accessible to the general public.
❓ 是什么让安全自行车比早期型号更受欢迎?
A. A. 它的座椅更舒适。
B. B. 它采用了链条传动和等大的车轮。
C. C. 它更轻便,更容易携带。
D. D. 它的前轮上装有脚踏板。
✅ 正确答案
B. It featured a chain drive and equal-sized wheels.