Define the following term: Ground level ozone

a. Comes from chemicals we emit. This is good for people and our environment.
b. Comes naturally from the air around us. This is bad for people and our environment.
c. Comes from chemicals we emit. This is bad for people and our environment.
d. Comes naturally from the air around us. This is good for people and our environment.

C.) comes from chemicals we emit. This is bad for people and our environment.

Ithink it is space that makes up 70 percent

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].