Which describes a constant in an experiment?
a. the variable changed by the experimenter
b. the quantity that must remain the same
c. the variable that changes in response to the experiment
d. the statement that is worded to test the experiment

What function does a limb serve in each animal how are the limb bones of the four animal similar based on the similarities what can be inferred about the evolution of the poor animals

The image below shows a common blood pressure gauge. what does this device do? a. measures the level of oxygen present in the blood b. measures the pressure of blood when the lungs expand and compress c. measures the electrical activity of the heart d. measures the pressure of blood when the heart contracts and relaxes

In each transformation of energy , some energy what?