饮用水净化的目的是（）。
A、杀灭病原菌
B、调节pH值
C、改善水质的物理性状
D、除去有毒物质
E、改善水温
参考答案：C
— So what did you buy?
— A T-shirt. It was a real _____. I got it for half price, saving 15 dollars. [ ]
A. cost
B. trade
C. business
D. bargain
絮集（絮凝）
