Good morning, everyone. Today we're going to look at the history of the bicycle. Now, you might think the bicycle is a fairly modern invention, but in fact, the first two-wheeled vehicle, called the draisine, was invented in Germany in 1817. It had no pedals, so riders pushed their feet against the ground to move. Later, in the 1860s, pedals were added to the front wheel in France, which made riding faster but also more dangerous. It wasn't until the 1880s that the chain drive was introduced, allowing the rear wheel to be powered, which is the design we still use today. So, to summarize, the key change that made bicycles safer and more practical was the addition of the chain drive.
❓ What does the lecturer say was the main advantage of the chain drive introduced in the 1880s?
A. A. It made bicycles faster than before.
B. B. It allowed the rider to power the rear wheel safely.
C. C. It removed the need for pedals entirely.
D. D. It made bicycles lighter and easier to carry.
✅ 正确答案
B. It allowed the rider to power the rear wheel safely.