污泥沉降比（SV）
参考答案：
混合液在量筒内静置30min后所形成沉淀污泥的容积占原混合液容积的百分率，以%表示。又称30min沉降率
He was admitted into Beijing University and years of his hard work ________ eventually.[ ]
A. paid off
B. were paid off
C. had paid off
D. had been paid off
广播
