In today's lecture, we'll discuss the history of the bicycle. The first two-wheeled vehicle, called the draisine, was invented in 1817 by Karl von Drais. It had no pedals; riders pushed their feet against the ground. However, it wasn't until the 1860s that pedals were added to the front wheel in France. This design, known as the velocipede, was popular but uncomfortable due to its rigid frame. By the 1880s, the 'safety bicycle' emerged with a chain drive and two equal-sized wheels, making it much safer and more practical. This design became the basis for modern bicycles.
❓ An toàn xe đạp đã có cải tiến chính nào so với các mẫu xe trước đó?
A. A. Nó có bánh trước lớn hơn.
B. B. Nó bao gồm bàn đạp ở bánh trước.
C. C. Nó sử dụng bộ truyền động xích và các bánh xe có kích thước bằng nhau.