Today we're going to discuss the history of the bicycle. The first two-wheeled vehicle, called the draisine, appeared in 1817 and was pushed along by the rider's feet. Later, in the 1860s, pedals were added to the front wheel, creating the velocipede. However, it wasn't until the 1880s that the chain drive was introduced, which allowed the rear wheel to be powered. This made riding much smoother and safer. Interestingly, the modern bicycle design, with two equal-sized wheels, became popular only after 1885, thanks to John Kemp Starley's safety bicycle. So, the key innovation that led to safer bicycles was the chain drive system.
❓ Según la conferencia, ¿cuál fue la principal ventaja de la transmisión por cadena introducida en la década de 1880?
A. A. Hizo las bicicletas más ligeras.
B. B. Le permitía al jinete sentarse más erguido.
C. C. Impulsaba la rueda trasera y hacía que montar fuera más seguro.
D. D. Eliminó la necesidad de pedales.
✅ 正确答案
C. It powered the rear wheel and made riding safer.