In paleoclimatology, researchers study ice sheets to reconstruct historical atmospheric compositions. The analysis of ancient ice core cylinders extracted from deep polar ice sheets, which contain atmospheric gases trapped thousands of years ago, _______ key evidence of past climate fluctuations. By examining these samples, scientists can improve the accuracy of future climate projection models.
Which choice completes the text so that it conforms to the conventions of Standard English?
- providesAnswer
- Bprovide
- Cproviding
- Dhave provided
Answer
provides
The singular verb 'provides' correctly agrees with the singular subject 'analysis.' The intervening plural nouns in the prepositional phrase ('cylinders,' 'sheets') and the relative clause ('gases') do not affect the grammatical number of the main verb.
Step-by-Step Solution
Key Concept
Subject-verb agreement requires the verb to match the grammatical number of the true subject, regardless of intervening prepositional phrases or relative clauses containing nouns of a different number.