Set 12: Form, Structure & Sense (Advanced)
Explanation
PASSAGE
The protein's three-dimensional structure, essential for its biological _______ was finally determined after decades of crystallographic analysis.
Which choice completes the text so that it conforms to the conventions of Standard English?
Detailed Answer Explanation
This question tests your understanding of sentence function and text organization. The phrase 'essential for its biological function' is an appositive phrase that is parenthetical. A comma closes this phrase before the main verb 'was finally determined.' Each sentence in a well-constructed text serves a specific purpose. Consider what role this sentence plays in the argument: does it introduce, support, contrast, or conclude an idea? Understanding why an author includes specific sentences helps you grasp the overall argument. Each sentence should serve a clear purpose: introducing ideas, providing evidence, acknowledging counterarguments, or drawing conclusions. Identify the role to understand the structure.
Key Evidence:
• "The protein's three-dimensional structure, essential for"
• "was finally determined"
Why others are wrong: C (A colon doesn't fit for closing an appositive phrase.), D (Missing punctuation fails to close the parenthetical appositive.), A (A semicolon is too strong for closing an appositive phrase.).
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