This problem is too complicated to be explained in a few words.

这个问题千头万绪，三言两语说不清楚。

《新英汉大辞典》

How never seems to be explained.

这似乎从未得到过解释。

youdao

The part which I acted is now to be explained.

我得在这里把我当初参与这件事的经过说明一下。

youdao

Jack London's many stories truthfully explained just how hard it was to be a gold seeker in eighteen ninety-seven.

VOA: special.2009.02.11

These are natural facts about the universe, but the naturalness needs to be explained and not merely assumed.

这些是宇宙自然现象，但自然现象需要被解释,而不仅仅是假定。

耶鲁公开课 - 心理学导论课程节选

Maybe there are certain supernatural things about communication from the dead or near-death experiences that need to be explained in terms of the soul.

也许有某些超自然的关于,亡者或是弥留之人的交流,或是,濒死体验,需要借助灵魂才能解释得通

耶鲁公开课 - 死亡课程节选

That distance needs to be explained, and the loop closed for the sake of public accountability.

WSJ: Review & Outlook: Let Benghazi's Chips Fall

This jump was too quick, too high to be explained by growing global demand.

FORBES: Silly Top Signs

It goes without saying that a joke that needs to be explained is a lousy joke.

FORBES: The Real Problem With That Groupon Super Bowl Ad