Answer:
external
Explanation:
<em>Through the process of photosynthesis, plants use the sun's energy to make sugars to function. External means from an outside force, while internal means from within. Since the sun isn't inside a plant, they gather it from outside, thus it's external.</em>
There is no picture for me to know what part is labeled b
<span>The circulatory system is vital in the exchange of oxygen with the cells in the animal's body because there is no living creature that can survive without oxygen, it keeps the body active.
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I agreed with him for 100%