the heart, blood vessels, kidneys, and bladder work together
gallbladder is bladder. circulatory_system is body_part. cardiac_valve_part is body_part. heart_valve is internal_body_part. all_humans has bladders human_kidney is body_part. heart_valve is body_part. kidneys is organs_in_body. kidneys is not organs_in_body. gallbladder is not bladder.