Good morning, class. Today we're going to discuss the history of the bicycle. You might think it's a simple invention, but its development took over a century. The first two-wheeled vehicle, called the 'draisine', appeared in 1817. It had no pedals; riders pushed their feet against the ground. In the 1860s, pedals were added to the front wheel, creating the 'velocipede'. However, this design was uncomfortable and hard to control. The breakthrough came in 1885 when John Kemp Starley introduced the 'safety bicycle' with a chain drive and two equal-sized wheels. This design became the basis for modern bicycles. Interestingly, the pneumatic tire, invented in 1888 by John Boyd Dunlop, was initially intended for bicycles, not cars.
❓ ¿Cuál fue la principal ventaja de la bicicleta de seguridad introducida en 1885?
A. A. Tenía pedales unidos a la rueda delantera.
B. B. Era más cómoda y más fácil de controlar gracias a su transmisión por cadena y sus ruedas iguales.
C. C. Fue el primer vehículo en utilizar neumáticos de aire.
D. D. Permitía a los ciclistas impulsarse con los pies contra el suelo.
✅ 正确答案
B. It was more comfortable and easier to control due to its chain drive and equal wheels.