The answer should be C, It diffuses from the alveoli into the blood.
Alveoli, also called the air sac, is the place where the oxygen we breathed in is exchanged with carbon dioxide that our body produces. Oxygen is passed into the blood in the capillaries through the process of diffusion, while carbon dioxide is diffused from the blood back to the alveoli, so that we can exhale the carbon dioxide after that.
Both a and b are not right because when we breathe in, the oxygen travels from the trachea to the bronchi, to the bronchiole, and to the alveoli, instead of directly into blood vessels like arteries, capillaries, or veins. d is also not right because the direction is wrong.
Therefore, your answer should be C.
there aren't many enzymes in food, mainly in fruits, the enzymes in friuts are very similar to ptylin found in the mouth that help break down sugar, they do not need to be ingested before they activate, a proof of this is the apple test, buy an apple, take a bite and leave it without covering it for a few minutes, you'll notice that the bitten part starts turning yellowish brown because the enzymes in the apple are already breaking it down.
In summary, they do not need to be ingested before activation, and the major characteristic of an enzyme is that they do not change after they react with (breakdown) food, so they are in the same form before and after they finish breaking down the food.
Answer:
Protein
EXPLANATION:
All of these substances are produced from protein metabolism.
Answer: A and C - When the moon is in alignment with the Earth and Sun, then the tides will be strongest.