A. Matching: match each word with the example that illustrates it. A. supply and demand B. competition C. consumer D. scarcity E. opportunity cost F. profit G. producer 1. Maria goes to the store and buys a new backpack. 2. Tyler mows lawns and does yard work for $10 per hour. 3. Gas Station A sells gas for $3.75/gallon. Across the street, Gas Station B sells it for $3.74/gallon. Gas Station A lowers its price to $3.74 -4. Liam spends $10 on lemonade mix and ice. On a hot day, he sets up a lemonade stand in his . yard. At the end of the day he has sold $20 worth of lemonade. 5. A car company made thousands and thousands of cars this year, but people haven't been buying as many cars. The car dealer lots are full. 6. Erin could make $24 this afternoon babysitting, or she could attend her grandma's birthday party. She decides to attend the party. She doesn't get the money, but her grandma is thrilled. 7. It's holiday time, and the hottest toy of the year sells out. People are paying ten times what it's worth online.

the earth’s crust is broken into separate pieces called tectonic plates (fig. 7.14). recall that the crust is the solid, rocky, outer shell of the planet. it is composed of two distinctly different types of material: the less-dense continental crust and the more-dense oceanic crust. both types of crust rest atop solid, upper mantle material. the upper mantle, in turn, floats on a denser layer of lower mantle that is much like thick molten tar.

each tectonic plate is free-floating and can move independently. earthquakes and volcanoes are the direct result of the movement of tectonic plates at fault lines. the term fault is used to describe the boundary between tectonic plates. most of the earthquakes and volcanoes around the pacific ocean basin—a pattern known as the “ring of fire”—are due to the movement of tectonic plates in this region. other observable results of short-term plate movement include the gradual widening of the great rift lakes in eastern africa and the rising of the himalayan mountain range. the motion of plates can be described in four general patterns:

collision: when two continental plates are shoved together

subduction: when one plate plunges beneath another (fig. 7.15)

spreading: when two plates are pushed apart (fig. 7.15)

transform faulting: when two plates slide past each other (fig. 7.15)