Well they actually observe 3 things. The color, mineral composition and the texture.
Rivers can provide water, sometimes food , and transportation.
I'm pretty sure its Nairobi, Kenya.
Answer:
The population of Africa has several specific characteristics:
- Very young: the population of Africa is very young, the median age in Africa is 19 years. For comparison, the median age in Europe is 43 years.
- High fertility: the average African woman has over 4 children, while the average European woman has 1 child or less.
- Very high population growth: because of the young population and the high fertility rate, the African population is growing very fast. Africa is projected to have over 4 billion people by the year 2100, currently, it sits at 1.3 billion people.
- Low life expectancy: the life expectancy in Africa has been improving, but it still low when compared to other parts of the world, sitting at around 60 years. For comparison, Japan, the country with the highest life expectancy on Earth, has a life expectancy of 84 years.
