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 actually, the first two-wheeled vehicle appeared in 1817, invented by a German baron named Karl von Drais. However, it had no pedals; riders pushed their feet against the ground to move. It wasn't until 1860s that pedals were added to the front wheel, creating the 'boneshaker'. Then in 1885, the 'safety bicycle' was introduced with a chain drive and equal-sized wheels, which became popular because it was much safer than earlier models. So, the key innovation that made cycling widely accessible was the chain drive system.
❓ Theo bài giảng, lợi thế chính của xe đạp an toàn ra đời năm 1885 là gì?
A. Nó không có bàn đạp, giúp việc điều khiển dễ dàng hơn.
B. Nó được vận hành bằng bộ truyền động xích, giúp an toàn hơn.
C. Nó có bánh trước lớn hơn để đạt tốc độ nhanh hơn.
D. Nó nhẹ hơn và rẻ hơn để sản xuất.
✅ 正确答案
It was powered by a chain drive, which made it safer.