Water flows through a selectively permeable membrane in a process called but water molecules cross the membrane more easily through channels of transmembrane proteins called

b.

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.

if you add everything up correctly you should get 69 i got this because 50 plus 19 is it