Answer:
A: light availability
B: nutrients
Explanation:
Both nutrients and light availability affect the primary productivity of the freshwater ecosystem, therefore, scientists study both factors to track associated changes. This is because photosynthesis is driven by sunlight and nutrients availability. It is suggested that the abundance of autotrophs (e.g. phytoplanktons) in an aquatic ecosystem increases as light and nutrients availability increase. Thus, there will be more food available for secondary and tertiary consumers to feed upon. Resultantly, the aquatic environment will turn a biodiversity hotspot where many species of living organisms start dwelling. Thus, scientists mainly ecologists would focus on these two parameters at first that lead to consideration of other parameters.
For more information, you may want to read this scholarly article
https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.4319/lo.2006.51.1.0288
An atom's smaller negative particles are at a distance from the central positive particles, so the negative particles are easier to remove.
D). Beliefs are not scientific.
Answer:
Rate of change of volume of the pile 
Explanation:
Given -
Rate of increase of the base of the pile
inches per minute
Height of the pile
the radius of the base
Let "h" be the height of the pile and "r" be the radius of the base.
Then 
Radius "r"
inches
Rate of change of radius i.e

Volume of conical pile

Change in volume of conical pile

Substituting the value of rate of change of radius, we get -

Rate of change of volume of the pile 
Answer:
The rabbit that best adapted to its environment was the gray rabbit.
Explanation: