Sore throat is a symptom, not a disease. In each case, there was a different cause that dictated a different treatment. The scratchy throat probably was a mechanical problem caused by dry, heated winter air and aggravated by my friend's tendency to breathe through her mouth when she sleeps.
Biogeochemistry includes the history of the great carbon reservoirs in the crust of the Earth, like limestone rocks and the coal deposits, as well as the distribution of nitrate and phosphate in the ocean.
The concepts of carbon reservoirs and fluxes are very important to understand the carbon cycle. Reservoirs are the total amount of carbon that is present in a component of the Earth that participates in the carbon cycle. These reservoirs are conveniently measured in the units of Gigatons of carbon, or GtC, which means a billion tons of carbon. The important reservoirs are: 1  Atmosphere: contains at present 750 GtC.