Why did british colonies in the south have the greatest number of slaves

Which of the following terms describes the layers of air surrounding the earth ?

Which of the following statements best characterizes changes to agriculture in the united states since 1900? a. increased mechanization has reduced the need for labor.b. increased mechanization has increased the need for water, thereby increasing the need for labor.increased mechanization has increased the use of land, thereby increasing the need for labor.d. increased mechanization has increased food production, thereby increasing the need for labor. select the best answer from the choices provided.

Find the coordinates of a if b(-9,-10) is the midpoint of ac and c has the coordinates of (-1,9)