Q: During subduction, one tectonic plate is forced below another. The subducting plate is forced into the

OPTIONS:
- asthenosphere.
- lithosphere.
- outer core.
- inner core.
A: asthenosphere.
Q: Sophie investigates the water supply at her school and the things that affect it. Which action is a direct observation?

OPTIONS:
- tasting water from a water fountain
- reading water test results
- studying the rules for purifying water
- investigating causes of water pollution
A: tasting water from a water fountain
Q: In some national parks, controlled fires are maintained by firefighters. Which of these is one of the major reasons for using controlled burns to maintain certain ecosystems?

OPTIONS:
- to give nonnative plants a chance to colonize the region
- to prevent the spread of pests that cause damage to plants
- to replace matured plants with saplings of the same species
- to rid the forest floor of accumulated deadwood and brush
A: to rid the forest floor of accumulated deadwood and brush
Q: Which is an example of a chemical change?

OPTIONS:
- sand separated from water by filtering
- water evaporating from a puddle
- a rock being eroded by wind
- a nail rusting in water
A:
a nail rusting in water