Good morning, everyone. Today we're going to discuss the history of the bicycle. Now, many people assume that the bicycle was invented in the 19th century, and that's partly true. The first two-wheeled, pedal-less machine, called a hobby horse, appeared in 1817. However, it wasn't until 1865 that pedals were added to the front wheel, creating the 'boneshaker'. This was followed by the high-wheel bicycle in the 1870s, which had a very large front wheel. But it was the invention of the chain drive in 1885 that made bicycles safer and more practical, leading to the modern design we recognize today. So, the key point is that the development took several decades.
❓ ¿Cuál fue el principal problema con la bicicleta de rueda alta mencionada por el conferenciante?
A. A. No tenía pedales.
B. B. Era difícil de equilibrar debido a su gran rueda delantera.
C. C. Era demasiado caro de fabricar.
D. D. No era adecuado para largas distancias.
✅ 正确答案
B. It was difficult to balance due to its large front wheel.