Good morning, everyone. Today we're going to discuss the history of the bicycle. Now, you might think the bicycle was invented in the 19th century, and you'd be right. However, the first two-wheeled vehicle, called the 'draisine', appeared in 1817. It had no pedals; riders pushed their feet against the ground. Later, in the 1860s, pedals were added to the front wheel, creating the 'boneshaker'. But it was only in 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.
❓ 是什么让安全自行车更易于大众使用？
A. A. 它没有踏板，而且很容易保持平衡。
B. B. 它采用了链传动和两个等大的轮子。
C. C. 它比早期的型号更轻便、更便宜。
D. D. 它由蒸汽驱动，因此所需的人力更少。
✅ 正确答案
B. It featured a chain drive and two equal-sized wheels.