2.佳句
(1)Pollution is, in fact, threatening our existence.
(2)Villagers are as a rule healthier than people who live in towns. One reason for this is that country air is fresher than the air in smoky cities.
(3)Most of the noise in the city comes from traffic, factories and construction sites.
(4)There is an increasingly loud voice from the public calling for firm action against pollution.