Good morning, class. Today we're going to discuss the history of the bicycle. Now, you might think the bicycle is a relatively modern invention, but its origins actually date back to the early 19th century. The first two-wheeled vehicle, called a 'Draisine' or 'hobby horse', was invented by Karl von Drais in 1817. It had no pedals; riders pushed their feet against the ground to move. However, it wasn't until the 1860s that pedals were added to the front wheel, creating the 'velocipede'. Interestingly, the invention of the chain drive in the 1880s allowed for a rear-wheel drive, which made bicycles much safer and more efficient. This design, known as the 'safety bicycle', became the basis for modern bicycles.
❓ Xe đạp an toàn có cải tiến quan trọng nào so với các thiết kế trước đó?
A. Nó có bánh trước lớn hơn.
B. Nó sử dụng bộ truyền động xích để dẫn động bánh sau.