代词pronoun简称pron是代替名词的一种词类.大多数代词具有名词和形容词的功能.英语中的代词,按其意义、特征及在句中的作用分为：人称代词、物主代词、指示代词、反身代词、相互代词、疑问代词、关系代词、连接代词和不定代词九种.
具体的可看在百度百科里查阅 http://baike.baidu.com/view/141.htm
It is generally accepted that we all need leisure time to recover from the stresses of work and everyday life.
这句话里面的代词有 it that we
Some people relax by watching movies, reading or surfing the internet. People who have physically demanding jobs may choose these types of activities. If you are a nurse or builder, you may feel that you don't want to do a five-kilometre run after work, because you are already physically tired.
这句话里面的代词有 some who these you that