Good morning, everyone. Today we'll discuss the history of the bicycle. The first two-wheeled vehicle, called the draisine, was invented in 1817 by Karl Drais. It had no pedals; riders pushed their feet against the ground. Later, in the 1860s, pedals were added to the front wheel, creating the velocipede. However, it was nicknamed the 'boneshaker' because of its rigid frame and rough ride. By the 1880s, the safety bicycle appeared with a chain drive and equal-sized wheels, making it much more stable and popular among both men and women. This design became the basis for modern bicycles.
❓ ¿Cuál fue la principal mejora de la bicicleta de seguridad en comparación con los modelos anteriores?
A. A. Tenía una rueda delantera con pedales.
B. B. Utilizaba una transmisión por cadena y ruedas de igual tamaño, lo que la hacía más estable.
C. C. Era más ligera y más barata de producir.
D. D. Tenía neumáticos de goma para un viaje más suave.
✅ 正确答案
B. It used a chain drive and equal-sized wheels, making it more stable.