Man has found out how effective we are at combating urban pollution. We not only breathe carbon dioxide in, and oxygen out, but also help to keep the air clean for people by trapping dust.
人類發現，我們是對抗都市公害的利器，不但吸收二氧化碳、釋放氧氣，為人類淨化空氣，還可以過濾塵埃。