If you drop a stone into a hole drilled all the way to the other side of earth, the stone will
a. speed up until it gets to the center of earth
b. slow down until it reaches the center of earth
c. speed up until it reaches the other side of earth
d. stop at the center of earth

It would probably disintegrate long time before that

I don't know for sure but I would say the answer is D.

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].