Enzymes are proteins and they control the speed of chemical reactions in your body. Without them, the reactions would happen too slowly to keep you alive.
Some break down larger molecules into smaller ones and those enzymes are in your stomach.
i'm sorry i didn't understand b and c but i can help you with a)
Explanation:
The human body has the ability to thermoregulate, so when the temperature rises, the blood vessels dilate, and the body emits more heat than it receives, and therefore sweat is released to cool the body. Hence, the higher the temperature the greater the sweating
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