The answer to the question "hot rock sometimes erupt thought openings in earths surface?" is volcanoes.

Here's why:

* Hot rock: Volcanoes are formed by molten rock (magma) from deep within the Earth's crust.

* Erupt: When the pressure from the magma becomes too great, it erupts through openings in the Earth's surface.

* Openings: These openings are called vents or craters.

So, the complete answer is: Hot rock, or magma, sometimes erupts through openings in the Earth's surface called vents or craters, forming volcanoes.