insatiable

他对知识的渴望永无止境。

He has an ___insatiable thirst for knowledge.

她对知识的渴望是如此强烈，永远无法满足。

Her ___insatiable thirst for knowledge can never be satisfied.

他对知识的渴求永无止境。

He has an ___insatiable thirst for knowledge that can never be quenched.