Riley rubs two rocks together. she notices that some of the surface of one of the rocks was worn away to form small particles. what has happened to that rock? was it eroded or weathered?

Given that Riley is a human, it's strange to use the terms erosion or weathering to describe her interaction with rocks. Nevertheless, Erosion is the transport of surface materials (soil, rocks, etc.) through the actions of wind, water, and ice, while weathering is the physical/chemical breakdown or change of objects due to weather conditions occuring mainly through the action of wind, water, and temperature on rocks and soil. This coupled with the fact that erosion occurs over a distance makes the best answer weathering.

Can you give me little more information

The answer to this question is  c. pharmaceutical accumulation  reclaimed water refers to the water that being used again after it already  used for agricultural purposes.this type of water often contains pharmaceutical accumulation because of the chemical fertilizer that is used for the plants is absorbed into the water.