Overcrowding and slums developed in many impoverished countries in the 20th century, mostly due to large migrations to cities from people looking for work.
One astronomical unit is equal to the distance from Earth to the Sun. The second option among all the options given in the question is the correct option. The distance as calculated in the year 2012 by the International Astronomical Union was equal to 149597870700 meters. Astronomers like to use this unit for measuring the distances between planets and other solar bodies.
I think that the two regions would be the Temperate Zone and the Polar Zone, as they're the only climate regions to the south of the 20<span>°S latitude. Check a world latitude map and compare it with a climate map if you're still unsure.</span>
