Though freed slaves seldom integrated with local populations once returned to their home countries and towns, humanitarian efforts returned freed slaves to which country and ports? a. nigeria, freeport, libertyville
b. angola, freetown (sierra leone), and libreville (gabon)
c. liberia, freetown (sierra leone), and libreville (gabon)
d. south africa, freeport, libertyville

The answer is B. Angola, Freetown (Sierra Leone), and Libreville (Gabon)

The highest point of a hill (or mountain) is a single point.
a single point can only be precisely marked with a dot. 
putting on a contour line is impossible  on a single point because the contour line is created after multiple points that have the same hight are marked, and after that, all of those points are connected with a line that creates a closed area. so the highest point, as said above, is a single point, there are no other points with the same height, so the only possible way for it to be marked is with a dot, and there is no possibility for a contour line.