The five main external factors that must be present or provided t sustain life are:
1. Water
2. Oxygen
3. Food
4. Atmospheric temperature
5. Atmospheric pressure
<span>The human body needs water, food and oxygen in order the body functions to work properly.
</span>Not every temperature is temperature at which the human can live. For example: we can not stay alive long period of time at temperature of 60 degrees Celsius.
Open ocean of any depth, where animals swim or float freely, is called the pelagic zone.
Hope this helped! :)
Answer:
A
Explanation:
A major role of the cell wall is to form a framework for the cell to prevent over expansion.
