A. how do index contours let you know if the land you are viewing is increasing or decreasing in elevation? b. what would you expect to find in an area with ten evenly spaced contour lines?

a. Various index contour has an elevation connected with it. When you look at 2 contours, one will have a greater corresponding elevation. As you go from the moderate elevation to the higher elevation, you know that the land is rising in the direction toward the higher elevation. From the higher to the lower elevation, the land is decreasing (sloping downward, declining in elevation).

b. Evenly spaced contour lines indicate a steady slope, uphill or downhill. The lines on a map that force variations in elevation are called contour line. A contour line is a line on a map that joins points of equal elevation. They show how steep a land form is. A contour line also is a function of two variables in a curve which has a constant value.

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation:

correct answer is a. and d.