Good morning, everyone. Today we're going to discuss the history of the bicycle. Now, many people assume the bicycle was invented in the 19th century, but its origins go back further. The first known two-wheeled, human-powered vehicle was created in 1817 by a German inventor named Karl von Drais. However, it had no pedals; riders pushed their feet against the ground. The real breakthrough came in the 1860s in France, when pedals were attached to the front wheel. This design, called the velocipede, was popular but uncomfortable due to its rigid frame and wooden wheels. Later, in the 1880s, the invention of the chain drive allowed for a safer 'safety bicycle' with two equal-sized wheels, which became the basis for modern bicycles.
❓ Según la conferencia, ¿cuál fue la principal mejora de la "bicicleta de seguridad" en comparación con los diseños anteriores?
A. A. Tenía un marco de madera más ligero.
B. B. Utilizaba una transmisión por cadena y ruedas de igual tamaño.
C. C. Fue inventada por Karl von Drais.
D. D. No tenía pedales y se impulsaba con los pies.