Question 90·200 Super-Hard SAT Reading Questions·Expression of Ideas
Many volcanologists expect that the island’s next eruption will be effusive rather than explosive, given the magma’s low gas content. ______ the 1875 eruption from the same vent, fueled by gas-rich magma, produced towering ash columns.
Which choice completes the text with the most logical transition?
For transition questions, first ignore the answer choices and read the sentences together, asking: How does the second idea relate to the first—same, opposite, cause/effect, example, or just time? Once you’ve named that relationship in your own words, eliminate any options whose function doesn’t match (for example, cross out cause/effect words if nothing is causing anything). Then pick the remaining transition that best matches the logical link you identified, even if it feels less “fancy” than others.
Hints
Compare the two eruptions
Focus on how the expected future eruption is described versus how the 1875 eruption is described. Are they similar or different?
Identify the logical relationship
Ask yourself: Is the second sentence giving a cause, giving an example, describing something happening at the same time, or describing a situation that opposes the first one?
Match relationship to transition types
Think about what each transition generally does: Which one signals a result, which one introduces an example, which one indicates simultaneous events, and which one connects two opposing ideas?
Step-by-step Explanation
Understand the first sentence
The first sentence says that many volcanologists expect the island’s next eruption to be effusive because the magma has low gas content. The key ideas are:
- Future eruption
- Effusive (gentle) behavior
- Low gas content is the reason for that expectation.
Understand the second sentence and its relationship
The second sentence talks about the 1875 eruption from the same vent, which had gas-rich magma and produced towering ash columns (a sign of an explosive eruption). This is very different from the kind of eruption described in the first sentence, so the relationship between the two sentences is that they describe two contrasting situations.
Match the relationship to the type of transition
Now look at what each type of transition would signal between these two sentences:
- A cause/effect link would say that one eruption caused the other or is a result of it (not true here).
- An example link would say the 1875 eruption is an example of the expected future eruption (also not true; they are opposite types).
- A time/simultaneity link would say both things happen at the same time (they clearly happen in different years).
- A contrast link would say: the new eruption is one kind, but the 1875 eruption was the opposite kind—which fits the passage.
Choose the transition that shows contrast
Checking the answer choices:
- “Consequently,” = result
- “For instance,” = example
- “Meanwhile,” = at the same time
- “By contrast,” = shows an opposite situation
Only “By contrast,” correctly signals that the 1875 eruption was different from the type of eruption volcanologists now expect, so A) By contrast, is the best choice.