维生素是我们不能缺少的生命元素。

Vitamin is what we can't lack.

youdao

但是你不知道有时候悲伤是我们生命中不能缺少的能量。

But what you didn't know is sometimes that grief becomes energy we can't live without.

youdao

我知道实现我的人生目标，过我想要的生活，唯一不能缺少的就是自信。

I know the only way I am going to reach my goals and live the life I want to live is to be confident.

youdao

Because of the lack of oxygen getting to the cells, the cells are no longer able to carry on their various metabolic processes.

由于细胞中缺少氧气,所以细胞不能完成,它们的各种新陈代谢活动

耶鲁公开课 - 死亡课程节选