Don't use words, expressions, or phrases         only to people with specific knowledge.     [ ]

A. being known              

B. having been known      

C. to be known                

D. known

从室外给水管网直接抽水的优点不包括( )。

A．充分利用外网水压，减小水泵扬程，节约电能

B．防止水在贮水池等构筑物中的污染和可能出现的溢水损失

C．省去贮水池、吸水井等构筑物，节省投资，节约用地，简化系统

D．充分利用外网水压，增大水泵扬程，节约能耗