Hi,
I researched all sources say between 1991-1997
Descriptive investigations involve collecting data about a system, but not making tests or experiments.
Making tests belongs to experimental investigations.
Descriptive investigations aim to draw conclusions from observations of the fenomena, while experimental investigations design tests that let the researcher to compare results on different conditions with a control situation.
There is also the so called comparative investigations which collect data from under different conditions but do not include the control situtation.
What made slavery legal was D. the Bill of Rights, Because amendment 13 officially abolished slavery in the United States and continues to this day.
So D. is your anwser.
Hope this helps. :)
Answer:
The Valley and Ridge area of Georgia is located southwest and northeast of the Appalachian Plateau. The ridges are an extension of the mountainous northwestern part of the state. The valleys, formed in between the mountains, create fertile soil that is perfect for the farming found throughout this region.
