Good morning, class. Today we'll discuss the history of the bicycle. The first two-wheeled vehicle, called the draisine, was invented in 1817 by Karl von Drais. It had no pedals; riders pushed their feet against the ground. In the 1860s, pedals were added to the front wheel, creating the velocipede. However, its solid rubber tires made rides very bumpy. The major breakthrough came in 1885 when John Kemp Starley introduced the Rover Safety Bicycle, which featured a chain drive to the rear wheel and equal-sized wheels. This design made cycling much safer and more comfortable, leading to the bicycle's popularity boom in the 1890s.
❓ Xe đạp an toàn Rover có lợi thế chính gì so với các mẫu xe trước đó?
A. A. Nó có bánh trước lớn hơn để đạt tốc độ cao.
B. B. Nó sử dụng bộ truyền động xích và các bánh xe có kích thước bằng nhau để đảm bảo an toàn.
C. C. Đây là mẫu xe đầu tiên có bàn đạp.
D. D. Nó có lốp cao su giúp cho chuyến đi êm ái hơn.
✅ 正确答案
B. It used a chain drive and equal-sized wheels for safety.