Will cattle grazing increase or reduce soil erosion?

Which process does not require the presence of a physical substance in order to transfer heat? air in the atmosphere is heated by the ground. this warm air then rises, and cooler air falls. this is an example of what type of process? how is conduction different from radiation?

When a septic tank backs up a goes in to clean it out

When a scientific theory has been tested and proved by the scientific community, it becomes a law