Today we're going to discuss the history of the bicycle. The first two-wheeled vehicle, called the draisine, appeared in 1817 and was pushed along by the rider's feet. Later, in the 1860s, pedals were added to the front wheel, creating the velocipede. However, it wasn't until the 1880s that the chain drive was introduced, which allowed the rear wheel to be powered. This made riding much smoother and safer. Interestingly, the modern bicycle design, with two equal-sized wheels, became popular only after 1885, thanks to John Kemp Starley's safety bicycle. So, the key innovation that led to safer bicycles was the chain drive system.
❓ Theo bài giảng, ưu điểm chính của bộ truyền động xích được giới thiệu vào những năm 1880 là gì?
A. A. Nó đã làm cho xe đạp nhẹ hơn.
B. B. Nó cho phép người lái ngồi thẳng lưng hơn.
C. C. Nó truyền động cho bánh sau và giúp việc đi xe an toàn hơn.
D. D. Nó đã loại bỏ nhu cầu sử dụng bàn đạp.
✅ 正确答案
C. It powered the rear wheel and made riding safer.