Good morning. Today we're going to discuss the history of the bicycle. The first two-wheeled vehicle, called the 'draisine', was invented in 1817 by a German baron. It had no pedals; riders pushed their feet against the ground. In the 1860s, pedals were added to the front wheel, leading to the 'boneshaker'. Later, the high-wheel bicycle became popular in the 1870s, but it was dangerous due to its large front wheel. Finally, in 1885, the 'safety bicycle' was introduced with a chain drive and two equal-sized wheels, which is similar to modern bicycles.
❓ ¿Cuál era el principal problema de la bicicleta de rueda alta en la década de 1870?
A. A. Era demasiado pesada para subir cuestas.
B. B. No tenía frenos.
C. C. Su gran rueda delantera lo hacía inseguro.
D. D. Requería que los jinetes se impulsaran con los pies.