Similarities between seemingly unrelated organisms can be explained by darwin’s theory that organisms come from common ancestors.

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.

i wish i could with all of them i can barley see the first one so here's the answer to the first one b