Today we're going to discuss the history of the bicycle. Although many people think of the bicycle as a relatively modern invention, its origins date back to the early 19th century. The first two-wheeled vehicle, called a 'velocipede', was invented in Germany in 1817. However, it had no pedals and was propelled by pushing your feet against the ground. Later, in the 1860s, pedals were added to the front wheel, leading to the 'penny-farthing' design, which had a very large front wheel. This was popular but quite dangerous. Finally, in the 1880s, the 'safety bicycle' with two equal-sized wheels and a chain drive was introduced, making cycling much safer and more accessible to the general public.
❓ Vấn đề lớn với xe đạp 'bánh to bánh nhỏ' (penny-farthing) là gì?
A. A. Nó quá đắt để sản xuất.
B. B. Nó không có bàn đạp và rất khó điều khiển.
C. C. Nó nguy hiểm vì bánh trước quá lớn.
D. D. Nó chỉ có thể được sử dụng trên những con đường bằng phẳng.