Good morning, everyone. Today we're going to discuss the history of the bicycle. One key figure is Karl von Drais, who invented the 'running machine' in 1817. This early bicycle had no pedals; riders pushed their feet against the ground. Later, in the 1860s, pedals were added to the front wheel, creating the 'boneshaker'. However, it was not until the 1880s that the 'safety bicycle' with a chain drive and two equal-sized wheels became popular, making cycling much safer and more accessible to the general public.
❓ ¿Cuál fue la característica principal de la 'bicicleta de seguridad' introducida en la década de 1880?
A. A. Tenía una rueda delantera grande y no tenía pedales.
B. B. Usaba una transmisión por cadena y dos ruedas de igual tamaño.
C. C. Funcionaba con un pequeño motor.
D. D. Requería que los jinetes empujaran los pies contra el suelo.
✅ 正确答案
B. It used a chain drive and two equal-sized wheels.