The question that most likely relates to the ecologist's observations and collected data is, 'Are fish dying due to reduced oxygen in the water?'
<h3>Research questions</h3>
Research questions are usually coined from observations. Observation is the first step in the scientific method. Once the research questions have been formed, hypotheses follow.
In this case, the ecologist, who happens to be the researcher in this case, observed that fishes were dying in large numbers. Fortunately for the researcher, he also observed that the lakes around the city where fishes were dying had significant algae growth as well as reduced oxygen levels.
The right questions to ask, therefore, should try and relate to observations together.
Thus, linking the death of the fishes to reduced oxygen levels in the lakes is the right question to ask.
More on research questions can be found here: brainly.com/question/27824868
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Answer:Oxygen is the most abundant element in the human body accounting for approximately 65% of a person's mass.
Explanation:
Because It is the most massive - containing about 99.8% of the mass of the Solar System
C is shows all ages in that country or area and which is declining as which is growing
