A, I think cuz we used glass slides in my high school for microscopes.
Answer:
this is my lazy guess but: human activity, differences in emitted energy from earth, and natural fluctuations. BUT DONT TRUST ME LOOK IT UP IM NOT SMART
Answer:
the mass of the system must remain constant over time
Explanation:
In other words matters cannot be created or destroyed, the overall amount will remain the same
The dirt sucks up the water from the surface to go to animals and plant and then becomes groundwater.
