combined drainage system造句

Thus it is very difficult to calculate the spill volume and water quality because they involve many processes such as rainfall , yield runoff of rainfall 、 flow concentration of surface runoff , ground pollutant build up 、 washout , the flow concentration of combined drainage system and cso
其中,合流制排水系统的溢流水量、水质的确定涉及到降雨,地面产流、汇流,地表污染物的累积、冲刷,污水在管渠中的汇流以及溢流等多种因素,采用一般方法很难定量计算。
It's difficult to find combined drainage system in a sentence. 用combined drainage system造句挺难的