Today we're going to discuss the history of the bicycle. While many people think of it as a simple invention, its development took over a century. The first two-wheeled vehicle, called a draisine, appeared in 1817, but 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 because of its rigid frame. It wasn't until the 1880s that the chain-driven 'safety bicycle' was introduced, which made cycling much safer and more popular, especially among women who gained new mobility.
❓ Vận tốc kế (velocipede) mà giảng viên đề cập có nhược điểm lớn là gì?
A. A. Nó không có bàn đạp.
B. B. Nó có khung cứng khiến người ngồi không thoải mái.
C. C. Nó quá nặng để phụ nữ có thể đi xe.
D. D. Không an toàn vì truyền động bằng xích của nó.
✅ 正确答案
B. It had a rigid frame that made it uncomfortable.