Good morning, everyone. Today we're going to discuss the history of the bicycle. The first bicycle, invented in the early 19th century, had no pedals and was pushed along by the rider's feet. It was called a 'hobby horse.' Later, in the 1860s, pedals were added to the front wheel, creating the 'velocipede.' However, this design was uncomfortable due to its rigid frame. In the 1880s, the 'safety bicycle' appeared, featuring equal-sized wheels and a chain drive, which made riding much safer and more efficient. This design became the basis for modern bicycles.
❓ Đặc điểm chính nào của xe đạp an toàn đã làm cho nó an toàn hơn và hiệu quả hơn?
A. Nó có thiết kế kiểu ngựa gỗ không có bàn đạp.
B. Nó có các bánh xe có kích thước bằng nhau và bộ truyền động xích.