The evolution of living beings have already passed for several billion years and valuable and limited organic resource or organic waste has accumulated in the nature. They include 500-600 million tons of crop straw each year in China, our urban rubbish stabilizes 150 million tons each year, just about 3 billion tons of dung and urine of birds and domestic animals, rural rubbish is about 360 million tons and partly mineral fuel. In traditional concept these matter can be treated as wastes with brushing off the nature thereby causing environmental protection. I persuade people need to change your conceptions and treasure organic resource.(to be proofread)
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