4

Set 6: Boundaries

Explanation

Answer: B

PASSAGE

The phenomena observed in the laboratory _______ to be replicated in field conditions, raising questions about the study's external validity.

Which choice completes the text so that it conforms to the conventions of Standard English?

A. is proving difficult
B. have proven difficult✓ Correct
C. has been proving difficult
D. has proven difficult

Detailed Answer Explanation

This question tests your understanding of sentence boundaries and punctuation. 'Phenomena' is the plural of 'phenomenon.' Use plural 'have proven.' To determine the correct answer, examine where complete thoughts begin and end. Look for independent clauses that need proper separation. A period, semicolon, or appropriate conjunction can correctly join or separate these ideas. When analyzing sentence boundaries, pay attention to how ideas flow from one sentence to the next. Correct punctuation ensures clarity and prevents confusion for readers. Review the options carefully to identify which choice creates proper sentence structure.

Key Evidence:

• "phenomena (plural)"

Why others are wrong: A ('Is proving' is singular.), C ('Has been proving' is singular.), D ('Has proven' is singular; 'phenomena' is plural.).

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