Today we're going to discuss the history of the bicycle. While many people think of the bicycle as a relatively modern invention, its origins actually date back to the early 19th century. The first two-wheeled vehicle, called a 'hobby horse', was invented by Karl von Drais in 1817. It had no pedals, and riders pushed themselves along with their feet. Later, in the 1860s, pedals were added to the front wheel, creating the 'velocipede'. However, this design was uncomfortable because of its rigid frame and metal wheels. It wasn't until the 1880s that the 'safety bicycle' with a chain drive and pneumatic tires became popular, making cycling much more practical and comfortable for everyday use.
❓ Vấn đề chính của xe đạp velocipede được đề cập trong bài giảng là gì?
A. Nó không có phanh.
B. Nó quá nặng để đạp lên dốc.
C. Nó không thoải mái vì khung cứng nhắc và bánh xe kim loại.
D. Vì bánh trước quá lớn nên rất khó lái.
✅ 正确答案
It was uncomfortable due to its rigid frame and metal wheels.