Environmental problems are becoming more and more serious all over the world.For example, cars have made the air unhealthy for people to breathe and poisonous gas is given off by factories. Trees on the hills have been cut down and waste water is being poured continuously into rivers.Furthermore, wherever we go today, we can find rubbish carelessly disposed.Pollution is, in fact, threatening our existence.
全世界的環(huán)境問題變得越來越嚴重。例如汽車污染的空氣影響了人們的呼吸,工廠釋放污染的氣體,山上的樹木被砍伐,污水不斷被排人河里。另外,無論我們走到哪里,到處可見隨意丟棄的垃圾。事實上,污染正威脅我們的生存。