How does the upper respiratory system support good health?

by moistening, heating, and purifying air as it proceeds down the airways

by removing dangerous carbon dioxide gases built up in the tissues

by providing oxygen to the cells

by preventing people from swallowing air

by moistening, heating, and purifying air as it proceeds down the airways

Explanation:

The upper respiratory system support good health by moistening, heating, and purifying air as it proceeds down the airways.

this would and i think the answer is d

exposure to hazardous carcinogens and toxic substances can cause breathing problems, such as copd and various types of cancer. it also increases the risk of heart attacks and strokes and has serious (but no less unattractive) side effects, such as aging, yellow teeth, a terrible smell and damage to the vocal cords.