Today we're going to discuss the history of the bicycle. Although many people believe the bicycle was invented in the 19th century, early prototypes appeared much earlier. The first known two-wheeled vehicle, called a 'draisine', was created by a German baron in 1817. It had no pedals; riders pushed their feet against the ground. Later, in the 1860s, pedals were added to the front wheel in France. However, this design was unstable and difficult to ride. It wasn't until the 1880s that the 'safety bicycle' with a chain drive and two equal-sized wheels became popular, making cycling accessible to the general public.
❓ Vấn đề chính của thiết kế xe đạp ban đầu có bàn đạp gắn ở bánh trước là gì?
A. A. Nó quá nặng để di chuyển.
B. B. Nó không ổn định và khó điều khiển.
C. C. Nó đòi hỏi quá nhiều việc bảo trì.
D. D. Nó chỉ có thể được sử dụng trên những con đường bằng phẳng.