C.
Weathering is the only one that doesn't deal with plate tectonics
Answer: salt
Freshwater is defined as having a low salt concentration, usually less than 1%.
Explanation:
Freshwater refers to the bodies of water that contain very low levels of dissolved salts. So, freshwater are unique for their low salt content (about 0.5% of salt) compared to the sea water with high salt content.
Examples of freshwater include rivers and spring
Natural regeneration of forests and woodlands is the process by which new trees grow from seeds that have fallen and germinate where they have fallen. The biggest problem with natural regeneration is that is unpredictable. As a result, it cannot be used for commercial farming. For most of the last two or three hundred years, forests and woodlands have restocked by using transplants grown in nurseries. The young trees are planted in equidistant rows. This allows each tree the best possible change of optimal growth.
That students who study make better grades than those who do not.