Select the statement that best describes how the process of plate tectonics circulates materials between the asthenosphere and the lithosphere. a. Some lithosphere becomes asthenosphere at mid-ocean spreading centers and reenters the lithosphere at subduction zones.
b. The materials that form the asthenosphere never mix with the materials that form the lithosphere.
c. Some asthenosphere becomes lithosphere at mid-ocean spreading centers and reenters the asthenosphere at subduction zones.

Amath expression is a collection of one or more terms, which are separated by the signs ( + , - , x , / ).example :   8+b8+b  or  a−3a−3in algebra, an equation is a mathematical statement with two expressions where, each expression is separated by an equal (=) sign. variables can be present on both the sides of the equality (=) sign and we use letters to denote such variables.example 1:   x=4+2x=4+2  , [here, we can observe that the variable is present only on one side of the equation].example 2:   2x+3=x+42x+3=x+4  , [here, we can observe that the variables are present on both side of the equation].

Answer. first blank ; ; ; clockwise; the second blank; ///clockwise;

The correct option to this statement would be true