Which river is africa's second longest river? nile river niger river gold river congo river

In the construction of new housing development, which factor of production can be categorized as land?

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?

Why do farmers in different regions use different farming techniques