Answer:
A. humans going underwater and exhaling
Explanation:
The dissolved oxygen in water refers to the amount of oxygen that is found in water. However, there are various ways that oxygen dissolves in a body of water, these includes;
- Photosynthesis of aquatic plants: Oxygen is the waste product of the photosynthetic process carried out by green plants. Hence, when aquatic plants undergo photosynthesis, oxygen from them tend to dissolve into water.
- Diffusion from the atmosphere: Oxygen from air or atmosphere also dissolves in water
- aeration as water moves over rocks and debris, and from wind and waves
However, humans do not exhale oxygen but carbon dioxide, hence, it is not a source of dissolved oxygen
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.
Because it could lead to possible treatment for spinal cord injuries diabetes and other diseases
AN EPIDEMIC is a disease that affects a large number of people within a community, population, or region. example coronavirus .
Petrifaction happens jvgocg igcgicigcicg
