1．An ageing society is one in which the population of people over the age of 60 is increasing.

　　老龄化社会是指60岁以上的人口数量持续增长的社会。

　　[句式分析]　该句为复合句。表语one后接in which引导的定语从句。

　　[佳句赏析]　这份工作是许多人想得到的。

　　The job is one that many people want to get.

　　2．There used to be factories which produced heavy smoke, gases and waste water.

　　这里过去有一些排出浓烟、气体和废水的工厂。

　　[句式分析]　used to do sth.表示"过去常常做某事"。There used to be ...表示"过去经常有......"。

　　[佳句赏析]　在我们镇，过去只有一所学校。

　　There used to be only one school in our town.

　　3．When passing the river, we had to cover our noses ...

　　当路过河边时，我们不得不捂住鼻子......

　　[句式分析]　when passing ...为状语从句的省略形式，其完整结构为：When we were passing the river ...。

　　[佳句赏析]　过马路时，小心车辆。

　　When crossing the street, look out for cars.

考点1 contribute v．促成，造成；对......起作用；捐助，捐献；投稿

　　[教材原句]

　　Measures to slow population growth like China's one­child policy, have also contributed to lowered birthrates.

　　像中国实行的只要一个孩子的减缓人口增长的措施对降低出生率也起到了作用。

　　The Rio 2016 Olympic Games contributed to the development of Brazil's economy.

2016年里约奥运会促进了巴西经济的发展。