Explain the main idea of the article in detail

c

explanation:

weathering - colorado river carves land in arizona to form the grand canyon. cracks form in a sandstone wall surrounding a house. a marble statue near the science museum is changing color due to rainfall

erosion - after a rainstorm, soil and rock piees litter the roadways. the sand dunes in the sahara desert are changing shape.

here's your answer.

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added