Today we're going to discuss the history of the bicycle. While many people assume the bicycle was invented in the 19th century, its origins actually go back much further. Early designs, like the draisine from 1817, were made of wood and had no pedals. Riders pushed their feet against the ground to move. Later, in the 1860s, pedals were added to the front wheel, creating the velocipede. However, this design was uncomfortable due to its rigid frame and metal wheels. It wasn't until the 1880s that the safety bicycle, with two equal-sized wheels and a chain drive, became popular, making cycling accessible to a wider range of people.
❓ Vận tốc kế (velocipede) được nhắc đến trong bài giảng có nhược điểm lớn nào?
A. A. Nó quá nặng để có thể đạp lên dốc.
B. B. Nó không có phanh để dừng lại.
C. C. Khung cứng và bánh xe kim loại khiến nó không thoải mái.
D. D. Nó yêu cầu người lái phải dùng chân đẩy trên mặt đất.
✅ 正确答案
C. Its rigid frame and metal wheels made it uncomfortable.