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 pushed along by the rider's feet. Later, in the 1860s, pedals were added to the front wheel. However, these early bicycles were very uncomfortable due to their solid rubber tires and rough frames. It wasn't until the 1880s that the safety bicycle, with two equal-sized wheels and a chain drive, became popular. This design made cycling much safer and more accessible to the general public.
❓ Theo bài giảng, điều gì đã làm cho xe đạp an toàn trở nên phổ biến hơn so với các mẫu xe trước đó?
A. Nó có bánh trước lớn hơn và bàn đạp.
B. Đây là mẫu đầu tiên sử dụng lốp cao su.
C. Nó có hai bánh xe bằng nhau và bộ truyền động xích.