D) all of the above is the correct answer
Some can others can't but most probablt will
Answer: A
Explanation: The blood–air barrier (alveolar–capillary barrier or membrane) exists in the gas exchanging region of the lungs. It exists to prevent air bubbles from forming in the blood, and from blood entering the alveoli. ... The barrier is permeable to molecular oxygen, carbon dioxide, carbon monoxide and many other gases.
Explanation:
Is a non-aggression pact or neutrality pact is a treaty between two or more states/countries that includes a promise by the signatories not to engage in military action against each other. Such treaties may be described by other names, such as a treaty of friendship or non-belligerency.
