A common remnant of life found in many areas from a specific time; this is used to help identify the age of rock layers and for relative dating.​

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?

What are some of the impacts of humans on the earth?

Modern democracies function as republics in which elected officials make decisions for the majority of the people.