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.
Considering that slavery originated sometime in the 1620s in North America, and that it lasted until 1865, the correct answer to how much it lasted should be around 245 years.
