Avolcanic eruption can be frightening and destructive, but it can also humankind. choose two positive outcomes of a volcanic eruption. 1.valuable metals can be found in ore near a volcano's base. 2.volcanoes emit greenhouse gases into the atmosphere. 3.volcanic ash is rich in minerals and makes for good fertilizer. 4.volcanic emissions improve air quality, those with respiratory problems.

The correct answers are:
1. Valuable metals can be found in ore near a volcano's base
3. Volcanic ash is rich in minerals and makes for good fertilizer
The magma from the volcanoes creates the igneous rocks, which are the hardest rocks, and also rocks predominantly composed by metals, so the volcanoes are a good candidate for finding quality ore.
The volcanic ash contains particles of lots of metals and it enriches the soil and makes it for a nice place to grow plants.

Dall of the above all of the choices make sense

Geothermic gradient is the rate of increasing temperature with respect to increasing the depth in the earths interior. away from tech tonic plates boundaries, it is about 25-40 c/km (72-87 degrees f/mi) of depth near the surface in most of the world.