Choose the most suitable option to replace the underlined part of the sentence. If the sentence is already correct, select 'No substitution required'.
The research paper was full of errors because the data is not verified by any expert.
Show answer & explanation
Correct answer: D
Explanation
The correct option to replace the underlined part of the sentence is "was not verified".
Explanation:
Tense Consistency: The main clause of the sentence uses the simple past tense ("The research paper was full of errors"). To maintain grammatical consistency, the subordinate clause explaining the reason should also be in the past tense.
Passive Voice: The sentence describes an action (verification) that should have been performed on the subject (the data) by an agent (any expert). Therefore, the past simple passive form (was/were + past participle) is required.
Subject-Verb Agreement: In this context, "data" is typically treated as a singular collective noun in general English usage, making "was" the appropriate auxiliary verb.