Most essential to use when giving ventilations to protect you and the victim from disease transmission

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.

bacterium is not correct

well, since there is no answer choices, i will give an answer on how it works : )

the two objects are placed together. energy will always be transferred from the hotter object to the cooler object until they are equal. hope this is close to one of the answer choices : )