Air pollution comes from factories, power stations and cars.Chemicals in the smoke from power stations cause a lot of damage.They can travel hundreds of miles in the wind before falling to the ground in the rain.But this "chemical rain" gradually destroys trees in the forests and kills fish in the lakes.In Germany, over 50% of the country's trees had been damaged by the year 1986.
空氣污染來自工廠、電站和汽車。電站發(fā)出的煙霧中所含的化學(xué)物質(zhì)造成很大的破壞。這些化學(xué)物質(zhì)可以隨風飄走幾百英里,然后才隨雨水降落地面。但是這種“化學(xué)雨”逐漸摧毀森林里的樹木,殺死湖泊中的魚。在德國,到1986年止,全國已經(jīng)有過半數(shù)的樹木被摧殘。