Cells are being constantly renewed.是什么意思？

Cells are being constantly renewed.

细胞不断再生。

cells

n. <生>细胞( cell的名词复数 )，小牢房，（修道士或修女住的）小房间，电池；

例句
An increasing body of evidence suggests that all of us have cancer cells in our bodies at times during our lives.
越来越多的证据表明，我们所有人一生中体内时有癌细胞存在。

are

vi. （用于第二人称单复数现在时，第一、三人称复数现在时）是；n. 公亩（等于100平方米）；

例句
We are scared to abandon ourselves to our feelings in case we seem weak or out of control.
我们不敢放纵自己的情感，以免显得太过软弱或缺乏自制。

being

n. 存在，生物，人，要素，本质；

例句
...expensive make-up that we saw being advertised by a beautiful model...
我们所见的由一位漂亮模特代言的昂贵化妆品

constantly

adv. 不断地，时常地，始终，一直；

例句
Her dedication constantly astonishes me.
她的奉献精神总是让我震惊。

renewed

adj. 更新的，重建的，复兴的，重申的；v. （使）复原， （使）更新，赋予新的生命和活力( renew的过去式和过去分词 )，重新开始，继续，补充；

例句
The renewed violence this week hardly augurs well for smooth or peaceful change...
本周新一轮的暴力事件预示着顺利平和的转变几乎不可能实现。