A study question about a researcher’s next test asks what the researcher expects if an idea is right. Start with the condition leading into the blank, then connect the proposed cause to what the researcher plans to examine. Apply the idea to the new case by asking what evidence that cause should leave behind, and keep any limits on time or place. Wrong choices often add details that sound scientific but have no support in the passage.
Hints
- Hint 1
The blank asks what Reyes assumed if her proposed eruption was real. Read that as a prediction under her idea, not as a request to prove that idea.
- Hint 2
Look at where the new cores came from and what Reyes searched for. How does that search connect to the two glacier records?
- Hint 3
Apply the proposed eruption to the marine cores. Use the original ice layers to work out the expected age and what would identify any new ash as part of that event.
Step-by-step
Turn the next search into a prediction
Step 1Read the proposal as a condition
Ice cores from glaciers 800 kilometers apart show identical spikes in volcanic ash particles, which Reyes links to a single, exceptionally large eruption. The blank asks what she assumed if that proposal was true, so we’re predicting what her next search would find, not proving that the proposal is right.
- Step 2
Explain the sites between the glaciers
Why examine locations between the two glaciers? A single eruption would have had to spread its ash far enough to reach both distant glaciers. The sites between the glaciers offer a new test of that idea: if the glacier records came from one event, Reyes expects evidence of its spread along the way. Her choice of sites shows where she expects to find traces, even though the passage hasn’t yet reported results from those sites.
- Step 3
Keep the expected age and ash signature
What would identify a new trace as part of that eruption? Reyes seeks the same ash signature, and the original layers date to about 12,800 years ago, so the ash pattern and date should match the ice record. The answer saying the signature would differ conflicts with that search. The prediction of layers much younger than 12,800 years adds a delay the passage never describes.
- Step 4
Use the full search area
Does only near the glaciers themselves explain why Reyes checks locations between the two glaciers? That limit leaves out the region her new search is meant to test. The choice predicting the same distinctive ash particles in layers from the same period gives the marine cores a way to connect the two glacier records to one eruption. Choice D.