Someone help!! Please! Someone explain Why we should have state testing please!

answer; ///the declaration of independence;

haile selassie i was the emperor of ethiopia from 1930-1974

changes in factors like average income and preferences can cause an entire demand curve to shift right or left. this causes a higher or lower quantity to be demanded at a given price. demand curves relate the prices and quantities demanded assuming no other factors change. it is important for consumers to know this information, because it is crucial for them to know what they can afford and can't afford. i hope this .