Mass- the amount of in an object

On this graph, the bottom horizontal line represents an ineffective price floor set above equilibrium. an effective price floor set below equilibrium. an ineffective price ceiling set above equilibrium. an effective price ceiling set below equilibrium.

What's erosion? a. the breakdown of rock into smaller pieces b. the removal of weathered products from rock c. a change in rock resulting from exposure to water d. a chemical change in rock that weakens it

What is a small water source like a stream or brook?