Ключевые слова: background, brown, canal, chemical, china, clean, concrete, construction, corrosion, dirty, drain, drainage, ecology, environment, equipment, factory, fatal, flow, flowing, fluid, garbage, global, grass, industrial, industry, liquid, natural, nature, old, outdoor, pipe, pipeline, pollution, problems, pump, refinery, river, rusty, season, sewage, sewer, stream, substance, technology, toxic, tube, warming, waste, water, waterfall,