Today we're going to discuss the history of the bicycle. As you know, the modern bicycle has two wheels of equal size, but early versions were quite different. In 1817, a German inventor created a wooden frame with two wheels, but the rider pushed along the ground with their feet. This was called a 'hobby horse'. Then, in the 1860s, pedals were added to the front wheel, making the 'penny-farthing' popular, which had a very large front wheel and a small rear wheel. However, this design was dangerous because riders could easily fall forward. It wasn't until the 1880s that the 'safety bicycle' with a chain drive and two equal-sized wheels was introduced, which is the basis for modern bicycles.
❓ Theo bài giảng, vấn đề chính của xe đạp penny-farthing là gì?
A. A. Nó quá nặng để có thể đạp lên dốc.
B. B. Người điều khiển có thể dễ dàng ngã về phía trước do bánh trước quá lớn.
C. C. Khung gỗ bị gãy dễ dàng.
D. D. Nó không có bàn đạp, vì vậy người đi xe phải dùng chân đẩy.
✅ 正确答案
B. Riders could easily fall forward due to the large front wheel.