Answer:
This is a primary source, namely a written one, because it derives directly from the past and its content hasn't been alternated.
Explanation:
Historians are dividing sources into primary and secondary. Primary sources are derived directly from the past, meaning that they are created at the time when some event happened. This is an example of primary source, as it is an original letter that one ruler sent to another one.
If a student wants to study the effect of sunlight on plant growth. In his experiment, 12 plants receive normal amounts of sunlight, but half of them are kept under bright sun lamps all night long. The control group is: the amount of light the plant receives.
<h3>What is control group?</h3>
A control group is a type of experiment carried out using two variables based on this control group can be defined as the process in which experiment is carried on two different variables such as dependent variables and independent variables in which one of the variables is not experimented or tested.
Based on the given scenario if after 6 weeks, the plants heights measured which inturn means that the control group is the amount of light the plant receives.
Therefore if 12 plants receive normal amounts of sunlight, but half of them are kept under bright sun lamps all night long. The control group is: the amount of light the plant receives.
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The first major Civil Rights action King was involved in was the "<span>c. Montgomery Bus Boycott," since this was a perfect way for King and his followers to implement a string of non-violent protests. </span>
<span>Characteristics were based on nationalism, where the leader was in total control of the state, they disregarded human rights& believed in censorship. They disliked democratic ideals because democracy focused on providing people with rights and good conditions for everyone as well as citizens being able to choose their leader.</span>
The answer you're looking for is Aristotle
