A

    Look! This is a picture of my teacher's family. This is Mr. Smith.  He  is my English  teacher. His wife is a doctor. She is nice. They have a son and a daughter. The boy's  name is Sam and the   girl's name is Kate. They are students. They are in the same school. They go to school on their bikes. Look! The son is like his mother. The daughter is like her father. Now they are all in China and can speak Chinese. They love China.

下列叙述中，正确的是（  ）

    在山区农村地区建设污水处理厂，普遍存在“建不起、养不起”的问题，作为山区的某县进行了多方探索，引进农村无动力厌氧污水处理技术化解了这一难题。所谓无动力厌氧污水处理系统就是人们常说的生化池，这种小型污水处理系统不需要任何设备也无需动力，只需利用生物软填料和碎石滤料就可达到吸附污染物过滤污水的效果。人工湿地上长满了美人蕉、芦竹、荷花等植物，周围建设了湿地公园并配备了健身器材，成为许多村民平时运动休闲的好去处。该系统治污效果良好，经处理后的水质达到了国家污水综合排放一级标准。

下图为某县农村无动力厌氧污水处理系统示意图。

分析山区农村地区推广无动力厌氧污水处理系统相较传统污水处理厂的优势。