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; riders pushed their feet against the ground to move forward. It was called the 'hobby horse.' Later, in the 1860s, pedals were added to the front wheel, creating the 'penny-farthing.' However, these were dangerous because riders sat high above the ground. The modern safety bicycle, with two equal-sized wheels and a chain drive, appeared in the 1880s and became popular due to its stability and ease of use.
❓ 根据讲座内容，前轮大后轮小的自行车（Penny-farthing）的主要问题是什么？
A. A. 它没有踏板。
B. B. 它太重了，没法骑。
C. C. 骑手们高高地坐在离地面很远的地方，这很危险。
D. D. 它不稳定，因为轮子大小不一。
✅ 正确答案
C. Riders sat high above the ground, making it dangerous.