Answer:
i think it is AAA or DDDD
Explanation:
The second line of defense of the immune system, also an aspect of innate immunity, is the nonspecific resistance. These defense mechanisms destroy invaders in a general way and do not target specific antigens.
It tell us the minimum heart rate for cardiovascular exercises
It shows us the heart rate that we need to achieve in order for our body to increase its metabolism above normal state, which resulted in increased calories burning.
Uncomfortable or squeezing chest pain, back pain, pain in arm(s), lightheadedness, shortness of breath, sweating.