a. rulers lost control of gao.
more than half of the population of the world live in cties. because of this liviing in a city has many down points like:
1.- city life can make us crazy. if you live in a city you have more probability to develop a mental disorder, 21% increased risk to develop anxiaty disorder, 39% increased risk to develop a mood disorder.
2.- the constant light don't let us sleep.
3.- the air is polluted. it increases the probabilty to develop asthma.
4.- the noise is terrible.
5.- rush hours are very common.
6.- there are uncaring crowds.
7.- all of these things affect our inmune system.