Question 52·200 Super-Hard SAT Reading Questions·Information and Ideas
Marine archaeologists had long classified the Selwick wreck, an early fifteenth-century merchant vessel found off England, as locally built. Their case rested largely on the hull’s pedunculate oak, a species common in eastern England. Dendrochronologist Mara Ivers’s team found that the oak’s year-to-year ring-width pattern instead best matched southern Baltic records, and oxygen-isotope ratios independently indicated the same region. These methods identify where trees grew, not where shipwrights worked. English customs ledgers list southern Baltic oak mostly as sawn timber, which could suggest assembly in England. Surviving vessel registers, however, often recorded a ship’s current home port rather than its construction site, so they cannot reveal how many supposedly English ships had been built abroad. Moreover, the Selwick’s joining techniques were used in both regions.
Which choice best states the main idea of the text?
For a main-idea question, separate conclusions that the evidence directly establishes from inferences that the passage limits. Compare each option against every major type of evidence in the passage, especially when an initially suggestive detail is later qualified by a problem with the records or methods.
Hints
Separate two kinds of origin
Distinguish the region where the trees grew from the region where the vessel was assembled.
Examine the apparent documentary clue
Consider why the customs ledgers might initially favor one route and why the vessel registers limit that inference.
Avoid unsupported rankings
Check whether the passage actually establishes that one construction site is more likely than the other.
Step-by-step Explanation
Identify the scientific conclusion
The ring-width pattern and oxygen-isotope ratios independently point to the southern Baltic as the region where the oak grew.
Evaluate the historical evidence
Although the customs ledgers list Baltic oak mostly as sawn timber, the vessel registers often identify ships by home port rather than construction site. The records therefore cannot establish how often completed Baltic-built vessels reached England.
Account for the structural evidence
The Selwick’s joining techniques were used in both English and Baltic shipbuilding, so they do not distinguish between construction in England and construction in the southern Baltic.
Synthesize the main idea
The best answer must distinguish the well-supported origin of the oak from the unresolved location of the vessel’s assembly. Choice C makes that distinction without treating either transportation route as more likely or established.