 "process paragraph : : Two large veins bring blood to the heart. The blood enters the right atrium. The blood flows through the tricuspid valve. The blood travels into the right ventricle. The blood goes through the pulmonary arteries to the lungs. Blood picks up oxygen in the lungs. Oxygenated blood enters the left atrium. Blood goes to the left ventricle. Blood leaves the heart via the aorta to the rest of the body. The deoxygenated blood returns to the heart. ", "event : The blood enters the right atrium.", "entity : oxygenated blood" 
 not exist 