What is the basic definition of evolution?

Ascientist wants to determine the effect of a new type of gasoline. he fillsone car with normal gasoline and another identical car with the new gasoline. which is the control group? a. the new type of gasolineb. the car with the normal gasolinec. the car with the new gasolinethe amount of gasoline usedd. the amount of gasoline used

Apopulation of black bears depends on salmon from a stream for food. if a drought causes the stream to run dry one year, how will this likely impact the black bear population?

Acceleration is a direct result of a.) balanced forces b.) unbalanced forces c.) gravity d.) velocity