这个古老洞穴的许多区域至今仍未被探索。

Many areas of this ancient cave are still ___unexplored.

这片未探索的雨林中可能有许多未知的物种。

There might be many unknown species in this ___unexplored rainforest.

这片热带雨林的生态系统仍有大量未被深入研究的领域。

The ecosystem of this tropical rainforest still has many ___unexplored areas.