第一段, 先說這一部分要研究什麼, 研究這個東西在自己的整個研究中的意義. The amount of profit is involved with the unethical recycling of "sewage oil"? A median person can recycle 4 barrels of oil, provide it at half the cost of new cooking oil, and make ten,000 RMB a month and that is the normal salary of a specialist. http://devin5wxx1.blogvivi.com/14806685/the-best-side-of-代寫論文