Answer:
What sends oxygenated blood back to the heart from the lungs?
Oxygen-rich blood flows from the lungs back into the left atrium (LA), or the left upper chamber of the heart, through four pulmonary veins. Oxygen-rich blood then flows through the mitral valve (MV) into the left ventricle (LV), or the left lower chamber.
Explanation:
It was D. government of that place on plato
Answer: heres the 3 main functions.
Explanation:
membranes have three primary functions 1) they keep toxic substances out of the cell 2) they contain receptors and channels that allow specific molecules, such as ions, nutrients, wastes, and metabolic products, that mediate cellular and extracellular activities to pass between organelles and between the cell and the outside environment and 3) they separate vital but incompatible metabolic processes conducted within organelles.
An independent variable is a variable which change is not affected by that of another variable. By process of elimination you can take out B and C. An independent variable can also change so that takes out A. That leaves D.