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 against the ground. By the 1860s, pedals were added to the front wheel, but this design was unstable. In 1885, the 'safety bicycle' appeared with a chain drive and two equal-sized wheels, making it much safer. Interestingly, the popularity of bicycles led to better road surfaces and even influenced the design of early automobiles. However, it wasn't until the 20th century that bicycles became affordable for the general public.
❓ ¿Qué hizo que la bicicleta de seguridad fuera más segura que los diseños anteriores?
A. A. No tenía pedales y se impulsaba con los pies.
B. B. Tenía transmisión por cadena y dos ruedas del mismo tamaño.
C. C. Tenía una rueda delantera más grande para mayor estabilidad.
D. D. Estaba hecho de materiales más ligeros.
✅ 正确答案
B. It had a chain drive and two equal-sized wheels.