Do you think migration was a voluntary move or involuntary? Why? (Help, I will follow you and give you free points if is correct)

Which statements about wells are true? check all that apply. a) wells bring groundwater from the unsaturated zone to the surface of the water. b) wells need to be drilled below the water table. c) if water is pumped from a well too quicky, the well may run dry. d) water from wells is generally not safe to drink. e) water gushes from artesian wells due to pressure.

The ozone hole is at its biggest each year in the ? hemisphere in the ? season.

Horizon a is also sometimes called a. topsoil b. subsoil c. bedrock d. weathered bedrock