Good morning, class. Today we're going to discuss the history of the bicycle. Now, many people think the bicycle was invented in the 19th century, but its origins actually go back further. The first two-wheeled vehicle, called a 'draisine', was invented by a German baron in 1817. It had no pedals; you pushed it with your feet. Later, in the 1860s, pedals were added to the front wheel in France. However, this design was dangerous because the front wheel was very large. It wasn't until the 1880s that the 'safety bicycle' with a chain drive and two equal-sized wheels was developed in England, which became the model for modern bikes.
❓ ¿Cuál era el principal problema del diseño de la bicicleta de la década de 1860?
A. A. No tenía pedales, lo que lo hacía lento.
B. B. La rueda delantera era demasiado grande, lo que causaba problemas de seguridad.
C. C. Era demasiado pesada para subir cuestas.
D. D. La cadena a menudo se rompía durante el uso.
✅ 正确答案
B. The front wheel was too large, causing safety issues.