The two characters form a single word, they cannot be separated.

这两个字构成一个词，不能拆开。

《新英汉大辞典》

But I say that they cannot be separated.

但是我说：它们是不可分的。

youdao

Language is the carrier of culture, they cannot be separated from each other.

语言是文化的载体，二者密不可分。

youdao

But,they note that mitigation and adaptation are linked and cannot be separated.

VOA: standard.2009.08.31

But they argue that organising cannot be separated from politics.

ECONOMIST: The labour movement

"The comments about failed drug tests made by the separated players in affidavits cannot be verified simply because they were made in the context of a drug buy, " she said.

WSJ: Drug Bust Hits TCU Football Program

Traditional chemical synthesis cannot distinguish between left- and right-handed versions, so they have to be separated afterwards, which is tedious.

ECONOMIST: Inhuman genomes