Blank (i)

The first sentence establishes the magnitude of human impact: even plentiful creatures now need intervention to survive. The second sentence begins: "The pretense that we might simply step back and let ecological processes unfold without us has become intellectually (i) ______ ." The word "pretense" signals that this idea is a false front, a delusion. Given the evidence in the first sentence, the idea of standing back is unjustifiable, untenable, or impossible to defend. The blank must mean impossible to justify or defend.
- A. unfashionable - Not in current style or favor. While letting nature take its course might be out of fashion, the sentence requires a stronger word about intellectual validity, not trendiness. Incorrect.
- B. indefensible - Incapable of being justified or defended; untenable. "Intellectually indefensible" perfectly captures the idea that the pretense of passivity cannot be rationally maintained given the evidence. Correct.
- C. inscrutable - Impossible to understand or interpret; mysterious. The pretense is not mysterious; it is wrong. Incorrect.

Blank (ii)

The semicolon is followed by: "indeed, our dominion is now so absolute that the duty of active stewardship is one we can scarcely (ii) _______." The word "scarcely" means "barely" or "hardly." If the duty is one we can scarcely do something with, that something must be avoid, shirk, or evade - because the duty is inescapable. The blank must mean renounce, reject, or cast aside.
- D. abjure - To renounce formally; to reject or abstain from. "A duty we can scarcely abjure" means a duty we can hardly renounce - i.e., an inescapable obligation. Correct.
- E. modulate - To adjust, regulate, or temper. "A duty we can scarcely modulate" would mean a duty we can barely adjust - which does not convey the inescapability of the obligation. Incorrect.
- F. arrogate - To take or claim without justification; to seize. "A duty we can scarcely arrogate" would mean we can hardly seize it - but the duty is already ours; the issue is whether we can evade it, not whether we can claim it. Incorrect.


Blank (iii)

The final appositive elaborates: "a responsibility that must be (iii) ______ rather than evaded." The contrast with "evaded" (avoided, shirked) requires a word meaning accepted, taken on, or embraced. The blank must mean taken up willingly, accepted as a burden.
- G. brandished - Waved or flourished menacingly or ostentatiously. "Brandished" implies aggressive display, not acceptance of responsibility. Incorrect.
- H. shouldered - Taken on as a burden or responsibility; accepted and borne. "A responsibility that must be shouldered rather than evaded" perfectly captures the contrast with "evaded." Correct.
- I. rescinded - Revoked, cancelled, annulled. This is the opposite of what is required. If a responsibility is rescinded, it is removed - it cannot then be evaded. Incorrect.