What keeps the life cycle of human

Suggest two reasons why irrigation is important for human development of the desert (4 marks)

Stages 1 and 4 of the demographic transition are similar in that

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?