Machine, Person, Human, Bicycle, Bike, Transportation, Vehicle, Soil, Urban, Wood, Construction, Building, Workshop, asia, east asia, china, beijing, peking, city, economy, economic, construction, work, worker, working, job, road, trafic, bicycle, sewerage, national capital, excavation, seat, landmass, district, wheeled vehicle, economical, vehicle, waste, metropolis, urban area, capital, difficulty, urban center, asian country, building, center, route, person, problem, sewage