It would refer to a number of related phenomena and patterns of change.
Answer:
Standards of living in Western European Contries are higher than the world average because the GDP Per Capita of Western European Countries is higher than the world average.
Standards of living in Western European Countries are also high because the governments of these countries offer many social services, either free, or at low costs.
Western European Countries are mostly peaceful, with only very localized crime and violence.
Finally, Western European Countries developed very fast during the latter half of the XX century, but economic growth has stagnated in recent decades.
All of the following are reasons why many rivers are unnavigable in Africa except the Nile is too shallow. The correct option among all the options that are given in the question is the third option or option "C". The Nile is not a shallow river but a huge river and so it is hard to cross. I hope the answer helps you.
