Which two body systems work together to deliver oxygen to cells? a. the digestive and respiratory systems b. the respiratory and circulatory systems c. the digestive and circulatory systems d. the circulatory and excretory systems

The correct answer is option B, that is, the respiratory and circulatory systems.  

The respiratory and circulatory system functions together to circulate oxygen and blood all through the body. The movement of air takes place in and out of the lungs via the bronchi, trachea, and bronchioles. The movement of blood takes place in and out of the lungs via the pulmonary veins and arteries, which associate with the heart.  

The pulmonary arteries mediate deoxygenated blood to the lungs from the heart, and the pulmonary veins carry oxygenated blood to the heart again so that it can be distributed to the rest of the body.  

The circulatory and respiratory systems work together to circulate blood and oxygen throughout the body. Air moves in and out of the lungs through the trachea, bronchi, and bronchioles. Blood moves in and out of the lungs through the pulmonary arteries and veins that connect to the heart.

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.