"生命极短暂的东西" can be translated into English as "things with an extremely fleeting/ephemeral existence" or more simply "things of extremely short-lived existence".
Here are two example sentences for context:
1、 Fireworks are things with an extremely fleeting existence, yet they bring us immense joy.
（烟花是生命极短暂的东西，却能给我们带来巨大的欢乐。）
2、 In the grand scheme of things, many material possessions are of extremely short-lived existence.
（从长远来看，许多物质财富都是生命极短暂的东西。）