It is either carcinogens or viruses (I think the first) I hope this helps!
Alveolar walls are thin to enable the quick passage of oxygen in and out of the lungs. The lungs works hand-in-hand with the heart and also is responsible in converting blood that's de-oxygenated into an oxygenated blood that is usable by the organ systems of the body. The alveolar walls are also designed to have thin membranes so that it can expand and constrict quickly allowing us to breather properly.
Answer:
Wind
Explanation:
Steel, coal and oil will all run out eventually
The Answer is B Latitude measures North and south,; Longitude measures East and west
This is the Reason I think its B is because Latitude implies the geographic coordinates that determine the distance of a point, north-south of the equator. Longitude alludes to the geographic coordinate, which identifies the distance of a point, east-west of the Prime Meridian.
<em>Hope this helps and can i please have brainliest ?</em>
