I think it would be the first ones with lower o2 because fish dont breathe oxygene
Answer:
Duodenum (option 3)
Explanation:
Digestion of carbohydrates, proteins, and fats continues in the small intestine. Starch and glycogen are broken down into maltose by small intestine enzymes. Proteases are enzymes secreted by the pancreas that continue the breakdown of protein into small peptide fragments and amino acids.
The duodenum is the first section of the small intestine and is the shortest part of the small intestine. It is where most chemical digestion using enzymes takes place
Respiratory system is refers to as the organs which are involved in breathing such as nose, throat, larynx, trachea, bronchi, and lungs. It is also known as respiratory tract.
The circulatory system is refer to as which contains the heart and the blood vessels and blood moves throughout the body in vessels. This circulatory system helps tissues to get enough oxygen and nutrients, and it helps them get rid of waste products.
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What is breathing?</h3>
When person inhale (breathe in), air enters in the lungs, and oxygen from atmosphere moves to body blood. At the same time, carbon dioxide, a waste gas, moves from blood to the lungs and is exhaled (breathed out).
Breathing process is known as gas exchange which is is essential to life.
For more information regarding breathing, visit:
brainly.com/question/15001725
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