While a constant supply of freshwater happens by itself in natural streams, an aquarium is by definition, a closed system. So here, man has to help out in order to provide new..
Answer:
wrong subject and none of theses is the answer :(
Answer:Increase in ambient global temperatures.
Recyling energy to be used again
Regulation of oxygen and carbon dioxide levels
An increase of erosion and siltation along waterways
Explanation:
Conservational biologists think about the preservation of ecosystem by maintaining the environment in a human control way.
Increase in ambient global temperatures.: The humans must prevent the increase in global temperature worldwide by preventing the rise of greenhouse gases which can lead to global warming worldwide.
Recyling energy to be used again: The sources of energy like wood, waste water can be recycled again for reutilization.
Regulation of oxygen and carbon dioxide levels.: The oxygen and carbon dioxide levels must be regulated. As oxygen is the basic requirement for respiration. The increase in carbon dioxide levels due to human activities is likely to cause respiratory diseases and health hazards in living beings.
An increase of erosion and siltation along waterways.: The erosion and siltation will likely to deposit nutrients and debris which may either contaminate the waterway or may cause eutrophication.
The answer to the fill in the blank is option B) Authentication
Passwords, tokens, and fingerprint scans are all examples of Authentication.
We use passwords, tokens and even fingerprints since they can be unique identifications and are usually seen as more secure.
In the above options, fingerprints are seen as the most secure form of authentication since everyone has unique fingerprints.
One of the earliest forms of authentication were time cards used as early as the 1950s and even unique keys and stamps used by early civilizations.
