What is the distance between points A(6,5) and B(0,13)

The primary agent of contact metamorphism is

Unlike other andean nations, chile has a relatively small population of mestizos people of european descent indians people of asian descent

This is a 2017 topographic map of puerto rico in the united states, and i'm sorry that people there have suffered such a disaster. i want to ask, what do the yellow dots and areas represent on this graph? and the blue area and the little blue circle, and the little blue sign that looks like a signal tower, what do they stand for?