Question 165·Hard·Form, Structure, and Sense
While analyzing soil samples taken from ancient riverbeds, geologist Priya Ramanathan used isotope dating to pinpoint periods of intense flooding, and in doing so, _____
Which choice completes the text so that it conforms to the conventions of Standard English?
For sentence-completion questions about Standard English conventions, first strip the sentence down to its core subject and verb so you can see the structure clearly. Identify what comes before and after conjunctions like "and" and check that both sides are parallel in form (both complete clauses if joined by a coordinating conjunction). Make sure modifiers such as "in doing so" clearly refer to the right noun, and check that any pronouns (like "she" or "it") have a clear, logical antecedent. Eliminate choices that create fragments, shift the subject illogically, or make the meaning confusing, then choose the option that preserves a clear, grammatical, and logically connected sentence.
Hints
Focus on who is doing the actions
Identify who used isotope dating in the first part of the sentence. Should the blank continue talking about that same person or something else?
Pay attention to "and in doing so"
The phrase "and in doing so," comes right before the blank. What kind of word or phrase should follow a coordinating conjunction like "and"—a complete clause or just a -ing phrase?
Check pronouns and clarity
Look at whether "she," "it," or "other researchers" makes the most sense right after "in doing so." Which choice makes it clear who "did so"?
Step-by-step Explanation
Understand the core sentence structure
First, ignore the blank and read the main part of the sentence:
"While analyzing soil samples taken from ancient riverbeds, geologist Priya Ramanathan used isotope dating to pinpoint periods of intense flooding, and in doing so, _____"
The structure is:
- Intro phrase: "While analyzing soil samples..."
- Main clause: "geologist Priya Ramanathan used isotope dating to pinpoint periods of intense flooding"
- Conjunction: "and"
- Phrase: "in doing so," followed by the blank.
Because of the word "and," what comes after the comma needs to work as a second action connected to what Ramanathan did.
Decide who "in doing so" refers to
The phrase "in doing so" refers to the action just mentioned: Ramanathan using isotope dating. That means it must logically describe something she did as a result of that action.
So after "and in doing so," we expect a clause that has Ramanathan (or a pronoun referring to her) as the subject and describes another result of her work.
Check for a complete, clear clause after "and in doing so"
After a coordinating conjunction like "and," we usually expect something grammatically similar to what came before: another complete clause, with a clear subject and verb.
So the blank should:
- Begin with the correct subject (referring back to Ramanathan), and
- Form a full clause (subject + verb), not just a phrase, and
- Keep the meaning and modifier "in doing so" logically connected to Ramanathan’s action.
Evaluate each choice with these requirements in mind.
Select the option that matches subject, structure, and meaning
Choice A, "she enabled other researchers to confirm that those events coincided with major climatic shifts", correctly:
- Uses "she" to refer back to Ramanathan (the person who was "doing so"),
- Provides a complete clause (subject "she" + verb "enabled" + object), and
- Clearly shows the result of her using isotope dating.
So the sentence reads smoothly and correctly:
"...geologist Priya Ramanathan used isotope dating to pinpoint periods of intense flooding, and in doing so, she enabled other researchers to confirm that those events coincided with major climatic shifts."