irrevocable

一旦签字，这份协议就不可撤销。

Once signed, this agreement becomes ___irrevocable.

极地冰盖的融化是气温上升带来的不可逆转的后果。

The melting of the polar ice caps is an ___irrevocable consequence of rising temperatures.

删除整个数据库被证明是一个不可挽回的错误。

Deleting the entire database turned out to be an ___irrevocable mistake.