Good morning. Today we're going to discuss the history of the bicycle. The first bicycle, invented in the early 19th century, had no pedals; riders pushed their feet along the ground. By the 1860s, pedals were added to the front wheel, but this design was unstable. It wasn't until the 1880s that the 'safety bicycle' with two equal-sized wheels and a chain drive became popular, making cycling safer and more accessible to the general public. This design remains largely unchanged today.
❓ ¿Qué hizo que la bicicleta de seguridad fuera una mejora significativa en comparación con los diseños anteriores?
A. Tenía una rueda delantera más grande para la velocidad.
B. Incluía pedales en la rueda delantera.
C. Usaba una transmisión por cadena y ruedas de igual tamaño para mayor estabilidad.
D. Fue la primera bicicleta sin pedales.
✅ 正确答案
It used a chain drive and equal-sized wheels for stability.