Answer:
C) tightly sealed containers
Explanation:
3, 5, 7, 1, 2
Since you have to use five of them, numbers 4 and 6 would not go into the plan. The order above is the one that makes most sense to me.
Answer:
the main site of gas exchange is in the lungs between the alveoli and a family of really small blood vessels called capillaries. Which are placed in the walls of the alveoli.
Explanation: