Good morning, everyone. Today we're going to discuss the history of the bicycle. The first bicycle, called the 'draisine', was invented in 1817 by a German baron. It had no pedals; riders pushed their feet against the ground. Later, in the 1860s, pedals were added to the front wheel, creating the 'velocipede'. However, it was very uncomfortable due to its solid rubber tires and rigid frame. It wasn't until the 1880s that the 'safety bicycle' with a chain drive and equal-sized wheels became popular, making cycling much safer and more efficient. This design is the basis for modern bicycles.
❓ Vận tốc kế (velocipede) có nhược điểm lớn nào được đề cập trong bài giảng?
A. Nó thiếu bàn đạp.
B. Nó không thoải mái vì lốp xe và khung xe của nó.
C. Nó có hai bánh xe với kích thước khác nhau.
D. Sản xuất nó quá đắt.
✅ 正确答案
It was uncomfortable because of its tires and frame.