I think the answer is several
Answer:To Prevent Bias which may arise from a major difference from personal characteristics.
Explanation: Sampling is a part of a population that is to be used for a research or experiment.
Variables are factors or members of a sample or Population that are can be altered (Dependent variables) in order to create an effect on another variables.
Independent variables are variables that are consistent and are not affected by other variables.
To Prevent BIAS,proper Sampling or inducing independent variables it must include all the factors necessary in an experiment or research.
Answer:
<em><u>Einstein first proposed a special theory of relativity in 1905 in his paper, “On the Electrodynamics of Moving Bodies,” taking physics in an electrifying new direction.</u></em>
E. They were the first written federal constitution of the United States.
