Humans (modern species, homo sapiens) first appeared during which period?

What type of pollution does household garbage cause

Sickle cell amelia is a condition condition where the red blood cells are deformed which is affected by sickle cell amenia

Match the correct terms to their descriptions a system in which only energy but not matter is exchanged frozen water in snow part of geosphere that includes only soil a thin layer between the troposphere and the stratosphere cryosphere tropopause closed system pedosphere