Why is it important for us to have our

lungs inside our bodies?

A. to keep them moist

B. to make them more eficient

C. to increase surface area to keep them moist be

Most likely to keep them moist, but I would argue that protecting them from outside elements is equally important if not more so. If the lungs were on the outside, then the water would evaporate away so thats likely what your teacher is going after.