There were no regulations in the meatpacking industry, they were paid poorly and there were no repercussions in acting as they did.
That is a good answer, add a bit of your personal fears (don't share here) and it will be good.
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 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.
