Answer: From the lungs.
Step-by-step explanation:
Because the left side of heart has to pump blood further into the body, the blood has to be oxygenated, thus the left side of the body receives oxygenated (oxygen) blood from the lungs and is carried by the pulmonary veins (these carry oxygen rich blood from the lungs to the heart). These veins carry oxygen rich blood from the lungs to the left artrium. Contraction of the left artrium allows blood to flow down to the left ventricle through the open mistral valves. Once the left central is full, the valves close and contraction of the left ventricle allows blood to flow the aortic valve to the aorta. The oxygenated blood is then carried from the left side of the heart to other parts of the body where it is needed and the aorta (an artery) carries oxgygenated blood away from the heart and further branches out into smaller arteries which distributes the oxygen rich blood to various parts of the body. Blood is pumped faster at a higher rate than the right side as the blood has to move a farther distance away from the heart.