Write T for True or F for False 12.Once a potential toxic substance goes into our society, it automatically produces an adverse effect. 13. External respiration refers to the exchange of gases between...

Write T for True or F for False

12.Once a potential toxic substance goes into our society, it automatically produces an adverse effect.

13. External respiration refers to the exchange of gases between blood and individual cells.

14. Sulfur oxides tend to reach deep into lung tissue while nitrogen dioxides tend to act in the upper moist airways of the respiratory tree.