Because once they are all gone we will not get them back for several millions of years or we may never get them back
In stage 1 the two rates are balanced. In stage 2 they diverge , as the death rate falls relative to the birth rate. In stage 3 they converge again, as the birth rate falls relative to the death rate. Finally in stage 4 the death and birth rates are balanced again but at a much lower level.
The population density of Europe, as a whole, is 143 people per square mile. This makes Europe the second most densely populated continent in the world, with the first place being occupied bu Asia, so we can say that Europe is a densely populated continent as a whole.
It has to be taken in notice that Europe is a continent that has an aging population, the fertility rate is very low, and the life expectancy is high. Interestingly enough, even though there's only three countries in the whole continent that have a positive fertility rate, the population of the continent is still growing, slowly, by 0.3% annually, but it is growing. The growth is mainly because of the migrants, mainly from the Middle East and Africa, and apart from increasing the number of the population with their entry, they also tend to have a high fertility rate.
Igneous rock derives it's name from the Latin word ignis which means fire. It is formed when the magma after volcanic eruption gets cool and solidified either on the surface of earth crust or inside the earth crust. These rocks are characterized by their hardness. These rocks undergoes no chemical weathering but exhibit very low mechanical or physical weathering may occur. Therefore, hardness is the property which can be used to identify the origin of an igneous rock.
Answer:
Yellow stars have the highest brightness
Explanation:
