Answer:
The explanatory variable in the Yale study is <u>which medication a subject was given.</u>
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Explanation:
The response variable in a study is the focus of the question of that study. In this particular case, what the study aims to know is whether a subject was able to stay off cocaine. The explanatory variable is the one that may or may not influence the response variable. In this case, what might influence the subjects is the medication given to him/her.
People in living in areas with steep mountains actually has an advantage when it comes to agriculture because there is already a free and vacant space that can be used to plant crops. In order to develop thesemountains into an area where planting is easily done, the people can create a stair-like structure on the edges of the mountains where they can plant crops that will be used daily and even sold in the market. This practice will be a very good strategy to make use of the steep mountain which is the only available natural resource at the time.
Answer: The Civil War started on April 12, 1861 and ended on April 9, 1865. The war erupted when Confederated bombarded Union troops at Fort Sumter; the war had several smaller battles involved and ended four years later.
Answer:
Trans-Sahara trade is one of the oldest trading networks in Africa.
Explanation:
The trading network requires to travel across the Sahara between sub-Saharan Africa and North Africa. Existing since prehistoric times, it reached its peak in the 8th century. In West Africa, the changes came in Ghana when the Almoravids sacked the city and the Ghāna Empire decline.
Mali rise in the 13th century as gold became the core of the trans-Saharan trade. The Trans-Sahara trade saw the rise of empires like Mali, Songhay, and Bono-Mansu. Expansion of urban centres and towns happened as Kano became one of the urban centres in West Africa. Trade also saw the rise of trading classes call the Wangara.
