in their lives还是in their life

1.生活 不可数
There are so many things to do in my life.
(在我的生活中有许多事情去做)

2.生命 可数
20 lives lost because of this accident.
(因为这场事故丢掉了20条生命)

Happy in their personal lives, Americans worry about country！

1.People come into your life for a reason,a season or a lifetime.(不可数n：“人生，生活, 一生”)

2.an earthquake that claimed hundreds of lives.（可数n）
地震造成几百人死亡（活人，人命：活的生命，尤指人）

3.the artistic life of a writer.
一个作家的艺术生涯生活：（构成存在的心理、智力和精神体验）

4.She led a good, long life.
她的一生幸福长寿（生命，不可数n）

5.the useful life of a car.
汽车的使用寿命(使用期，有效期：某物存在或工作的时间)

应该是in their life
life是名词,in their life就是在他们的生活中
live是动词吧...初一的一点模糊的印象,有句话叫,She lives in Beijing.
例句:life:http://www.baidu.com/baidu?ie=gb2312&ct=1048576&cl=3&word=life+
live:In the storm,the Browns lost their lives ______(include) their pet dog. all their life与all their lives 哪个对? in their Reaganite phase when love lives in heaven When love lives in heaven 翻译but when they did,their lives changes Starz In Their Eyes 歌词 Ambivalence in their eyes是什么意思.? my mother lives (in on ) China when love lives in heaven 的中文歌词