An inference question asks you to finish the text’s reasoning from the clues it gives. Read the words leading into the blank to see whether you need a conclusion or a claim the evidence challenges. When a new finding is set against an older view, put each in a few words and ask how they differ. Then predict the smallest conclusion the clues support. Wrong choices often add a claim the text never tested.
Hints
- Hint 1
Look at what the words before the blank ask for. Is the missing idea something the recordings support or something they challenge?
- Hint 2
The first sentence gives the naturalists’ view. Compare that view with the order of sounds in the recordings, and ask which part of the view that order tests.
Step-by-step
Test the older view against the recordings
Step 1Identify the belief under review
Naturalists call the wood thrush’s return the surest early sign of spring in the northern forests. Their field notes often start spring entries with its song, which explains why they hold that view. What does the blank need us to do with this claim? The phrase casting doubt on the idea that asks us to name a belief the new evidence weakens, so the ending must be about what the recordings call into question.
- Step 2
Compare when the sounds begin
How does the new timing compare with the old view? The recordings show that, in most years, chorus frogs begin calling two to three weeks before wood thrush songs are first detected. Those calls provide an earlier sign that can be heard, and the pattern repeats across years rather than coming from one unusual spring. So our small prediction is that the recordings weaken the bird’s claim to come first.
- Step 3
Match the claim being challenged
Compare our prediction with earliest reliably observable sign. Earliest means coming first, and reliably observable means you can count on being able to detect it. The repeated earlier frog calls challenge the wood thrush’s claim to come first, which makes this a belief the recordings weaken. This fits casting doubt on the idea that without claiming that the bird’s song has no value as a spring sign. Choice A.