A confined aquifer is
A. separated from the main groundwater
B. Found between two impermeable layers
C. Found in the unsaturated zone
D. The top layer of the saturated zone

When in solution, a molecule that moves slowly across an artificial membrane moves rapidly across a plasma membrane. this molecule rapidly enters the cell regardless of whether its concentration is higher inside or outside the cell. using this information, which transport mechanism is most likely to be responsible for the movement of the molecule across a plasma membrane? view available hint(s)when in solution, a molecule that moves slowly across an artificial membrane moves rapidly across a plasma membrane. this molecule rapidly enters the cell regardless of whether its concentration is higher inside or outside the cell. using this information, which transport mechanism is most likely to be responsible for the movement of the molecule across a plasma membrane? active transportexocytosis

Ascientific idea becomes valid when it is what?

Why are current extinctions of concern to enviromentalists?