Answer:
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. The pulmonary vein empties oxygen-rich blood, from the lungs into the left atrium.
Explanation:
hope this helps...
and if u didn't get it its veins...
Frequency, Intensity, Time, and Type (FITT)
Genes in the DNA tell the cells which proteins to produce, which determines certain traits
