【正文】
eing 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 hil ls 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. 環(huán)境問題變得越來越嚴重的世界各地。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。樹木在邊境 ls 一直不斷減少 ,廢水被倒進河流。另外 ,無論我們走到今天 ,我們可以找到垃圾隨意丟棄。事實上 ,污染是威脅我們的生存。