Exercise 3: sample answer

Three reasons: (1) Roads were poor, so the machine worked only on smooth surfaces, and riders on pavements caused complaints and bans (check). (2) It was tiring: pushing a heavy wooden machine with the feet offered little advantage over walking except on flat, smooth ground. (3) It was a fashion, expensive and mocked, and the novelty wore off. The most important was probably the lack of any drive other than the feet, because that limited its usefulness whatever the roads were like; pedals solved that problem later (Chapter 3).