Emotional and physical stress are ofter caused by loss.
this is because apart from B)Loss. everything is positive. Exercising will release endorphin which will make you happy. relaxing will make you feel calm and achieving your goals will encourage you to do more.
therefore the answer is B) Loss
The exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them.
Hope this is helpful!
The answer is vaccination! hope this helped ;)
