9. b) determination of the amount of a substance that is available to the internal organs of the body d) the time period between initial exposure and a measurable response. c) the study of the adverse effects of chemicals on living organisms." those members of a population who are capable of developing a disease are known as:

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 erosion,oil spills,pollution,tourism,urban development;

Why you put last one a? i think is b.