You would want this observation to be in an area with a lot of biotic and abiotic factors, so the best place for it is an ecosystem.
The answer is option B "declining number and variety of the species in an area." Biodiversity is a variety of life for example a ecosystem has many species which makes it a biodiversity. Now a loss of a biodiversity would be loosing a huge amount of species in that area or ecosystem which would mean the answer is option B.
Hope this helps.
The term for blue skin caused by lack of oxygen is cyanosis. One is said to be cyanotic when presenting with this discoloration.
Answer:
A closed circuit doesn't allow the flow of electrons. an open circuit does. example: if you turn off a switch in your house. you 'broke the circuit it is closed.
