In the following question, few sentences are given with two blanks in each. Select the pair of words that best completes both blanks in all the sentences, ensuring the sentences remain grammatically correct and contextually appropriate.

(I) He ____________ that the sudden ____________ in temperature signals an approaching storm.
(II) The committee ____________ the ____________ of the project’s budget is justified by the expanded scope.
(III) She ____________ that his recent ____________ to department head will bring positive changes.

The correct answer is presumes; elevation.

Step-by-Step Explanation:

Let us analyze how the chosen pair of words fits into all three sentences both grammatically and contextually:

1. Sentence (I): "He presumes that the sudden elevation in temperature signals an approaching storm."

- First blank (presumes): A verb in the third-person singular present tense is required. "Presumes" means supposes or takes something to be true on the basis of probability, which makes complete sense here.

- Second blank (elevation): A noun is required following the adjective "sudden". "Elevation" refers to a rise or increase, so an "elevation in temperature" contextually describes a temperature rise.

2. Sentence (II): "The committee presumes the elevation of the project’s budget is justified by the expanded scope."

- First blank (presumes): Fits grammatically with the collective noun "committee" (treated as singular here) and contextually means the committee supposes or assumes something to be true.

- Second blank (elevation): An "elevation of the project's budget" refers to an increase or hike in the budget, which aligns with the rationale of an "expanded scope."

3. Sentence (III): "She presumes that his recent elevation to department head will bring positive changes."

- First blank (presumes): Correctly expresses her belief or assumption regarding the outcome.

- Second blank (elevation): "Elevation" here denotes promotion or advancement to a higher rank/position (i.e., being elevated to department head).

Why other options do not fit all three sentences perfectly:

- assumes; drop: While "assumes" works for the first blank in all sentences, a "drop in temperature" works for sentence (I), but a "drop of the project's budget" or "drop to department head" does not fit the context of sentences (II) and (III).

- captures; promotion: "Promotion to department head" works for sentence (III), but "promotion in temperature" or "promotion of budget" is semantically incorrect for sentences (I) and (II).

- infers; acceleration: "Acceleration in temperature" or "acceleration to department head" is contextually unnatural in English usage.

Therefore, the word pair presumes; elevation is the only pair that completes all three sentences with grammatical accuracy and cohesive context.