life泛指“生命”时是不可数名词;泛指“性命”时是可数名词;泛指“生活”时是不可数名词,其前不加冠词,但指某种有比较具体内容的“生活”“生活方式”时则是可数名词。
People tend to work hard at this stage of life.
人在这个人生阶段往往发奋努力。
The operation could prolong his life by two or three years.
这次手术可使他多活两三年。
They had got too used to the soft life at home.
他们实在是过惯了家里的安逸生活。