活性污泥的脱水性能较差，其相关因素有（）
A.泥龄
B.污泥指数
C.半小沉降数
D.污泥浓度
参考答案：A, B
The next programme will start in 10 minutes; in the , here's some soft music. [ ]
A. time
B. meantime
C. way
D. means
多管制热水热网
