There is really nothing to know. All you have to use is context clues and common sense. We know some synonyms for direct are manage and handle. Indirect means not direct, right? And we can't handle or manage earth's interior (core), right? Therefore, the study of earth's interior is an example of indirect observation because we cannot directly manage it.
In Geography, when you mention characteristics, it refers to the actions and the ideas of man that changes or changed the Earth. Characteristics in Geography can also refer to as the natural and current features seen all around the Earth.
When flying long distances, a world aeronautical chart (WAC) for the determination of height, position,alternative landing areas,airspace boundaries and radio frequencies.
<u>Explanation:</u>
For those aircraft flying at higher distances, WAC is used for the purpose of navigation. This chart is very helpful in finding current position, alternate routes, safe heights for flying,etc. It also helps in choosing the best alternate route for reaching the desired location. It provides the person flying at higher distances with that of radio frequencies and airspace boundary.
Strategic planning can be done for flights with this chart. Using this chart we can view the whole area of flying. There is a revision of these charts every year but for the areas like Mexico and Caribbean since the revision takes place once in 2 years.
Answer:
I think the border between Djibouti and Somalia is Ethiopia.