The method when an ecologist sets up a greenhouse and measures the effects of different levels of carbon dioxide on an endangered plant species is called experimenting. I hope that this is the answer that you were looking for and it has helped you.
If an ecologist sets up a greenhouse and measures the effects of different levels of carbon dioxide on endangered plant species, he is conducting an experiment. An experiment is a procedure that is meant to provide support, refute or validate a particular hypothesis. It is also meant to be repeatable and logical. Experimenting is an important step in the scientific method.
"<span>d. The Southern plantation economy depended on slavery" is the best option from the list, since although slavery continued to exist to some extent in the North it was the South's primary source of labor. </span>
The French and Indian War began in 1754 and ended with the Treaty of Paris in 1763. The war provided Great Britain enormous territorial gains in North America, but disputes over subsequent frontier policy and paying the war's expenses led to colonial discontent, and ultimately to the American Revolution.
He was the top general during the Civil War, Lincoln knew he was the man to hold the union together. If not for Grant, our southern states might be a separate country