Answer: North Pole
Explanation: On Oct 12th, 2020 the largest expedition ever undertaken came to an end after researchers spent over a year studying climate change and ice drifting in the Arctic.
The answer is <span>Time is the independent variable, and the number of birds is the dependent variable. </span>
<span>An independent variable is variable that is not affected in the experiment. It is what experimenter controls. On the other side, a dependent variable is called dependent because it depends on the independent variables. It is what is affected during the experiment.
In Sam investigation, he controls time - he counts birds at 6 a.m. and 6 p.m. So, time is the independent variable. The number of birds is affected during the experiment, so it must be the dependent variable.
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C causes central nervous system damage to humans