n.排水，放水；排水系统；排走物，废水；排水区域 双语释义：n.(名词)[U]排水,放水 the act or action of draining[U]排水系统,下水道 system of drains[U]废水,污水,污物 sth that is drained off英英释义： drainage[ 'dreinidʒ ]n.emptying something accomplished by allowing liquid to run out of it同义词：drain