Question 180·Hard·Boundaries
The researchers analyzed over 2,000 fossil _____ generating a database that has become a crucial reference for paleontologists worldwide.
Which choice completes the text so that it conforms to the conventions of Standard English?
For boundaries questions, first decide whether the text after the blank is an independent clause or a modifier phrase (like an participial phrase). If it’s a modifier phrase describing the result of the main clause, a comma is usually the correct choice; eliminate semicolons when the following text cannot stand alone as a complete sentence.
Hints
Check what comes after the blank
After the blank you see "generating a database..." Does that part have its own subject, or is it an phrase?
Decide whether you need a full sentence after the punctuation
Ask: does the part after the blank work as a complete sentence? If not, eliminate punctuation that requires an independent clause after it.
Read the sentence aloud for natural pauses
Try each option and listen for where a natural pause belongs between the main clause and the result phrase.
Watch out for over-punctuation
Be careful not to split a tight phrase like "thereby generating" with an extra comma in the middle.
Step-by-step Explanation
Identify the main clause
Read the sentence without the extra modifier:
- Subject: "The researchers"
- Verb: "analyzed"
- Object: "over 2,000 fossil specimens"
So the core independent clause is: "The researchers analyzed over 2,000 fossil specimens."
Identify what follows the blank
After the blank, the sentence continues: "generating a database that has become a crucial reference for paleontologists worldwide."
This begins with an verb ("generating") and does not have its own subject, so it is a participial phrase describing the result of the main action.
Match punctuation to the structure
A participial result phrase that modifies the whole preceding clause is typically set off with a comma:
- Comma: can introduce a nonessential/result modifier (works here).
- Semicolon: must be followed by an independent clause (does not work here).
- No punctuation: makes the modifier run into the noun right before it and can create a confusing attachment.
Select the choice that creates a clear, grammatical sentence
The best standard punctuation is a comma before the result phrase:
"The researchers analyzed over 2,000 fossil specimens, thereby generating a database that has become a crucial reference for paleontologists worldwide."
Therefore, the correct answer is specimens, thereby.