Set 10: Form, Structure & Sense (Advanced)
Explanation
PASSAGE
Marine biologists have observed that coral reefs, once thought to be _______ are actually dynamic ecosystems capable of significant adaptation.
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 'once thought to be static' is a parenthetical interruption. It needs a closing comma before 'are actually' to properly resume the main clause. 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:
• "coral reefs, once thought to be"
• "are actually dynamic ecosystems"
Why others are wrong: C (A semicolon is too strong for closing a parenthetical phrase.), D (A colon doesn't fit here; this is resuming the main clause.), B (Missing punctuation fails to close the parenthetical phrase.).
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