Please help !! a___ is the annual variation in the flow of a river

The model of human settlement suggests that uthe model of human settlement suggests that urban growth is patterned around transportation networks such as railroads and highways. a. burgess b. hoyt c. sauer d. von thunenrban growth is patterned around transportation networks

Where does the availability of water pose the greatest problem

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?