Good morning, everyone. Today we're going to look at the history of the bicycle. Now, you might think the bicycle was invented in the 19th century, and you'd be right. But the first two-wheeled vehicle, called a 'velocipede', appeared in France in the 1860s. It had pedals on the front wheel, but no brakes. This made it quite dangerous. Later, in the 1870s, the 'penny-farthing' became popular in Britain, with a huge front wheel and a small rear wheel. However, it was unstable and difficult to mount. It wasn't until 1885 that the 'safety bicycle' with two equal-sized wheels and a chain drive was introduced, which is the design we still use today. So, the key improvement in the 1880s was the addition of the chain, making the ride much safer and more efficient.
❓ Theo bài giảng, lợi thế chính của xe đạp an toàn ra đời năm 1885 là gì?
A. A. Nó có bánh trước lớn hơn để đạt tốc độ cao.
B. B. Nó sử dụng bộ truyền động xích và các bánh xe có kích thước bằng nhau, giúp an toàn hơn.
C. C. Đây là chiếc xe đạp đầu tiên có bàn đạp.
D. D. Nó nhẹ hơn và dễ mang theo hơn.
✅ 正确答案
B. It used a chain drive and equal-sized wheels, making it safer.