An independent variable is that which is: A. Kept constant.
B. Observed to develop a hypothesis.
C. Changed by the scientist.
D. Measured by the scientist.

A kept constant

Explanation:

The concept In math is an independent variable

C. Changeed by the scientist

Explanation:

An independent variable is also known as the test veriable. It is the one you change to get a different result is the dependent variable a.k.a the out come variable. Hope this helps!

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.