Yúgāng lǐ de qīngdàofū bāngzhù bǎochí shuǐzhì qīngjié.
The scavenger fish in the tank helps keep the water clean.
Tips
usage
清道夫 has several uses: a street cleaner (literal), a sweeper in soccer, and also a type of armored catfish (also called 琵琶鼠) popular in aquariums that feeds on algae.
