What is the main purpose of controlled variables in an experiment?

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

When plants use sunlight to make food, the energy of sunlight is

In the practice of science, this type of reasoning is used to develop explanations.