Increases in urban population reflect three separate forces: the natural rise in population within urban areas; the migration of rural dwellers to urban areas; and, as settlements expand and become more densely populated, the reclassification of rural settlements as urban. All three forces have been at work to varying degrees. But where the third factor is significant, it creates a particular problem, because the administrative machinery for urban areas seldom exists for such settlements.
Urbanization brings noise pollution due to a larger population. This can be seen as one challenge. Another challenge is pollution such as plastic, gases, noise, etc due to the larger population. Also a big challenge is danger. You do not know the people as much in a larger town, therefore the danger to you is a lot more prominent.
The Sun is a main - sequence star, and thus generates its energy by nuclear fusion of hydrogen nuclei into helium. In its core, the Sun fuses 620 million metric tons of hydrogen each second.
Marble (metamorphic rock), Limestone (sedimentary rock) and Quartzite (metamorphic rock). THE TOWER OF PISA- The Tower of Pisa is the bell tower of the Cathedral.
