n.清洁；洁白
In open cycle condition,the frequency of the cleanness should base on cooling water quality. 在开式循环的情况下，清洁的间隔时间长短要根据冷却水的性质而定。
The white in the shoes symbolizes purity and cleanness. 球鞋中的白色象征着纯洁和洁白。
