The Gobi Desert is surrounded by mountains on one side and China on its southern border Hope this has helped :)
Answer:
hot-air balloons
Explanation:
More recently, aerial photographs have often been taken from fixed-wing aircraft and today can even be taken from unmanned aerial vehicles (also knowns as drones).
A. Canyons and sedimentary deposits
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.
