The hardest mineral is with a hardness of
a. quartz; 1
b. quartz; 10
c. diamond; 1
d. diamond; 10

What are four key elements of the study of economics?

Some mining processes involve removal of large areas of earths surface in the mined region this practice causes severe environmental damage by allowing which natural process to accelerate in the affected areas? a.precipitation b.erosion c.migration d.condensation

The distribution of related animals and plants across the world