SummarizationRead each of the following short paragraphs and complete the phrase or sentence that expresses the main idea of the paragraph. The first letter of the missing word is given before the blank.Paragraph 5.One system using solar energy to clean up pollution in water has banks of moving mirrors that focus sunlight onto a waterfall of waste water. The other method reflects light from a mirrored trough onto waste water flowing through glass tubes. The solar purifiers will reduce concentration of organic pollutants to a few parts per billion.5.Two methods for water t_______with solar energy.
【正确答案】：treatment
【题目解析】：P163
