Good morning, everyone. Today we're going to discuss the history of the bicycle. Now, many people think the bicycle was invented in the 19th century, but its origins actually go back further. In 1817, a German inventor named Karl von Drais created a two-wheeled contraption called the 'running machine', which had no pedals. Riders pushed their feet against the ground to move. This was later improved in the 1860s in France, when pedals were added to the front wheel. However, these early bicycles were very uncomfortable due to their solid rubber tires and rough frames. It wasn't until 1885 that the 'safety bicycle' with a chain drive and equal-sized wheels became popular, making cycling much safer and more accessible to the general public.
❓ Vấn đề chính của những chiếc xe đạp thời kỳ đầu trước năm 1885 là gì?
A. A. Họ không có phanh.
B. B. Họ cảm thấy khó chịu và không an toàn
C. C. Chúng quá đắt
D. D. Chúng chỉ có thể được sử dụng trên những con đường bằng phẳng