Answer:
This is the best explanation for why there is such a small amount of phosphorus that moves into aquatic systems:
1. Phosphorus is highly stable in the atmosphere and remains there for long periods of time.
Explanation:
The phosphorus first cycle is the process by which the phosphate ion passes in very small amounts through the lithosphere from volcanic aeorosols, then to the hydrosphere, where it stays from 20,000 to 100,000 years in the ocean, and finally to biospherere, where rain and erosion helps washing the phosphorus from the rocks into the soil. So, raining is the beginning of the phosphorus´s second cycle, so it is also, the slowest one of the matter cycles that is why the natural total background phosphate levels in several bodies of freshwater range from 0.005 to 0.05 mg/L. Phosphorus remains mostly on land and in rock and soil minerals.
Although abundant on our planet´s sedimentary rock crust and in human body, phosphorus to commercialize is only found in minerals therefore, phosphates mining activity and calcium heating is the only way to get it in its pure elemental form. It is an essential nutrient for plants and animals and a big percentage of the mined phosphorus is used to make fertilizers.
Answer:
B
Explanation:
The point of the islamic spring was to get rid of the dictaors. Next, there has been huge economic decrease and an increase of terrorist violence.
Answer:
<em>Catholic church:</em>
<em>The crusades contributed to increase the wealth of the church and the power of the papacy. The popes took over the enterprises authority and influence, by placing their hands, their armies and resources of Christendom and adapted the people to look at them as leaders.</em>
<em>Thousands of the crusaders, returning broken in spirits and in health sought an asylum in monasterie-retreats, and along with them were their wordly goods.</em>
<em>The Crusades:</em>
<em>The Crusades were military campaigns sanctioned by the Catholic Church in the Middle Ages.</em>
<em>Effects of the crusades:</em>
<em>The crusades kept all Europe in tumult for two centuries and cost Christendom several millions of lives. The holy wars affected indirectly and became an important factor in the history of the progress of civilization.</em>
