Scientists long debated the origins of chondrules, tiny glass beads that formed in meteors billions of years ago. For decades,...
GMAT Expression of Ideas : (Expression) Questions
Scientists long debated the origins of chondrules, tiny glass beads that formed in meteors billions of years ago. For decades, different theories were proposed, from lightning strikes to powerful rock collisions, but none had sufficient evidentiary support. ________ scientists found strong evidence that chondrules were formed by shock waves in nearby nebulae.
Which choice completes the text with the most logical transition?
Step 1: Decode and Map the Passage
Part A: Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "Scientists long debated the origins of chondrules, tiny glass beads that formed in meteors billions of years ago." |
|
| "For decades, different theories were proposed, from lightning strikes to powerful rock collisions, but none had sufficient evidentiary support." |
|
| "[MISSING TRANSITION]" |
|
| "scientists found strong evidence that chondrules were formed by shock waves in nearby nebulae." |
|
Part B: Passage Architecture & Core Elements
Visual Structure Map:
[BACKGROUND: Long-standing scientific debate about chondrules] → [PROBLEM: Decades of theories but no sufficient evidence] → [MISSING TRANSITION] → [BREAKTHROUGH: Strong evidence found for shock wave theory]
Main Point: After decades of unproven theories about chondrule origins, scientists finally discovered strong evidence pointing to shock waves in nebulae as the cause.
Argument Flow: The passage establishes a long-running scientific mystery, describes the inadequacy of previous explanations, then presents the breakthrough that resolved the debate with solid evidence.
Step 2: Interpret the Question Precisely
This is a fill-in-the-blank question asking us to choose the best logical connector. The answer must create the right relationship between what comes before and after the blank.
Step 3: Prethink the Answer
- The transition needs to connect two contrasting situations: first, we have decades of theories with no sufficient evidence, and then we have scientists finding strong evidence
- The logical relationship here is temporal—this represents the end of a long process of unsuccessful attempts
- The transition should signal that after this long period of uncertainty, a resolution has finally been reached
- So the right answer should indicate that after a prolonged period of failed attempts, a successful breakthrough occurred
- "For example" introduces a specific instance of something general
- But the strong evidence isn't an example of the previous unsuccessful theories—it's the opposite
- This would create a logical disconnect since examples should support the preceding statement
- "Therefore" indicates cause and effect
- But there's no causal relationship between the lack of evidence and scientists finding evidence
- The discovery wasn't caused by the previous failures
- "Similarly" shows comparison or parallel situations
- But finding strong evidence is the opposite of having no sufficient evidence
- This would create a contradiction rather than a logical flow
- "Finally" indicates the conclusion of a long process
- This perfectly captures the temporal progression from decades of unsuccessful theories to the breakthrough
- It signals that after the long period of debate without resolution, scientists at last found the answer they were seeking