Don't leave the tap running after use.

用后将水龙头关紧。

Don't leave the tap (水笼头) running.

不要一直开着水龙头。

Tom, turn off the tap. Don't leave it running.

汤姆，把水龙头关了。别让它一直流。

Don't keep the tap running when you leave.

你离开时别让水龙头开着。

To save water, I often try to reuse it for watering flowers after washing hands or vegetables and seldom do I leave the tap water running when showering or washing.

节约用水，我经常尝试重用它洗手后浇花或者蔬菜，很少做我离开当洗澡或洗运行的自来水。