clean
adj.洁净的;干净的;爱干净的;爱整洁的;无有害物的;无污染的
v.除去…的灰尘;使…干净;打扫;变干净;清除内脏
adv.(行动)彻底地,完全地
n.打扫;清扫
The law would encourage companies to switch from coal to cleaner fuels
该法律将鼓励企业转而使用比煤更加清洁的能源。
The beach was the cleanest and most beautiful they had ever seen.
那儿的海滩是他们所见过的最干净、最漂亮的海滩;
Maybe it is the cleanest seas and rivers in the world.
可能是世界上最干净的海和河了吧。