application or intradermal injection of a substance to the skin to test the body's reaction to it. Such a test detects an animal's sensitivity to such allergens as dust and pollen, or to preparations of microorganisms believed to be the cause of a disorder.
A direct relationship graph is a graph where one variable either increases or decreases along with the other. The general equation for a direct relationship graph is y = mx + b, where y denotes the...
Ok direct relationship or proportionality is a mathematical concept. This concept has been used to make the formulas of Laws of Motion but I don't think the other can be done. Since a mathematical relationship is an abstract concept and Laws of motion applies to bodies with mass.