Answer:
Borders are imaginary lines that divide a nation, state, province or city from others. These dividing lines can be taken from geographic features, such as rivers, seas, lakes, mountains, etc .; or in geometric form, using lines as meridians and parallels; or for ethnic reasons, dividing populations based on languages, ethnic origin, etc.
Examples of each of these types of border are:
-Natural border between Argentina and Chile along the Andes Mountains, taking as the dividing line the highest point of the same.
-Geometric border between America and Canada on the west coast, taking the line of parallel 49 as division.
-Ethnic border between Pakistan and India, dividing both nations according to concepts of Islamic or Hindu religious affiliation.
In the 31 countries at the bottom of the list, 28 of which are in sub-Saharan Africa, a person can hope to live on average only 46 years, or 32 years less than the average life expectancy in countries of advanced human development, with 20 years slashed off life expectancy due to HIV/AIDS.
Answer: To locate the epicenter of an earthquake, scientists must have seismograms from at least three seismic stations.
Explanation: I hope this helps:)