Kate gathered three boxes of the same size made of different materials: glass, clear plastic, and aluminum painted black. she placed them on a window sill in the sun for an hour and then measured the warmth of the air in each box. in this experiment the warmth of the air is an?

The answer is Free factor  / Independent variable.

Explanation:

A free factor is a variable that is controlled to decide the estimation of a needy variable s. The reliant variable is what is being estimated in a trial or assessed in a scientific condition and the autonomous factors are the contributions to that estimation. An autonomous variable in a test setup is the controlled variable. As it were, the free factor is the variable that is being tried or modified by the experimenter.

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.