Good morning, class. 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 propelled by the rider's feet pushing against the ground. 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. It wasn't until the 1880s that the 'safety bicycle' with a chain drive and two equal-sized wheels became popular, making cycling much safer and more accessible to the general public.
❓ Điều gì đã làm cho xe đạp an toàn trở nên phổ biến hơn so với các mẫu xe trước đó?
A. A. Nó có ghế ngồi thoải mái hơn.
B. B. Nó có bộ truyền động xích và các bánh xe có kích thước bằng nhau.
C. C. Nó nhẹ hơn và dễ mang theo hơn.
D. D. Nó có bàn đạp gắn vào bánh trước.
✅ 正确答案
B. It featured a chain drive and equal-sized wheels.