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:
Ok idk if there was a picture that was supposed to go with that cause I don't see one but here are some vestigial structures in humans: Appendix, Pinky toe (debatable possible used for balance) , ear muscles, tail bone, wisdom teeth, nictitating membrane, male nipples (sorry to be gross), and goosebumps. Those are the ones I can remember. Hope this helps!
Answer: It’s B. testing the device on model cars in laboratory conditions
Explanation: Using real cars can just cause more actual accidents if the device doesn’t work.