Where do the respiratory and circulatory systems meet? a. in the heart b. in the muscles c. in the lungs d. in the brain

Option C. The lungs.

Explanation:

Alveolis are the air sacs in the lungs which main function is to get oxygen into your bloodstream and carbon dioxide leaves the blood.

The alveolis are located in the lungs, and it's where the respiratory and circulatory systems meet, for the reasons stated before.

Therefore, the correct option is Option C.

burning of wood and coal

explanation:

the panel also concluded there's a better than 95 percent probability that human-produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in earth's temperatures over the past 50 years.