Set 3: Inferences (Intermediate)
Explanation
PASSAGE
Geologists have discovered that the Sahara Desert was once a green savanna, with lakes, rivers, and abundant wildlife. This transformation occurred about 5,000 years ago due to subtle shifts in Earth's orbital patterns that altered monsoon circulation. The change happened gradually enough that human populations adapted by migrating toward the Nile.
What can be inferred about climate change and human adaptation?
Detailed Explanation
This question asks you to draw a logical conclusion from the text. Change was 'gradual enough' for populations to adapt by migrating—pace allowed survival. A valid inference must be supported by evidence in the passage, even if not stated directly. Look for clues in the text that strongly suggest the answer. Avoid conclusions that require assumptions beyond what's written. Valid inferences are strongly supported by multiple pieces of evidence in the text. Be cautious of choices that go too far beyond what the passage actually states. The best inference is the one most directly supported by textual evidence.
Key Evidence:
• "happened gradually enough"
• "human populations adapted by migrating"
Why others are wrong: A (Orbital shifts caused the transformation.), B (It was 'once a green savanna.'), D (Gradual change allowed adaptation.).