Question 59·Medium·Form, Structure, and Sense
Despite early skepticism from her peers, British chemist Rosalind Franklin _____ a pivotal technique known as X-ray crystallography, enabling later scientists to visualize the structures of complex molecules.
Which choice completes the text so that it conforms to the conventions of Standard English?
For verb tense questions in historical or scientific context passages, first identify the time frame: is the sentence about a completed past event, something ongoing, or a hypothetical situation? Look for clues like dates, historical figures, and words such as "later" or "eventually." Then quickly eliminate choices whose tense suggests the wrong time or meaning (ongoing, present-connected, or hypothetical) and select the form that cleanly states the completed action, often the simple past for historical achievements.
Hints
Look at the time clues
Ask yourself: Is the sentence talking about something happening now, something connected to the present, something hypothetical, or a completed historical action?
Consider who Rosalind Franklin is
Rosalind Franklin is a historical scientist who lived in the 20th century. What kind of verb tense usually describes the achievements of historical figures?
Eliminate mismatched tenses
Remove any options that suggest an action happening right now or a hypothetical situation. Focus on the option that presents her work as a completed fact in the past.
Step-by-step Explanation
Identify the time frame and context
Read the whole sentence and notice that it is about British chemist Rosalind Franklin, a historical figure. The phrase "Despite early skepticism from her peers" and the mention of "enabling later scientists" both point to a completed event in the past that affected scientists who came after her.
Match the verb tense to a completed past action
You need a verb form that describes something Franklin actually did in the past, with the action completed.
- A verb that suggests something is happening right now would be wrong.
- A verb that connects the past action directly to the present (as if she were still alive and the action still relevant to now) would be awkward for a historical figure.
- A verb that suggests a hypothetical or "would do" situation would not match a factual statement of what she actually did.
So we are looking for the choice that simply states a finished action in the past.
Evaluate each option and choose the one that fits
Now test each choice:
- is refining – present progressive; means she is doing it now. That does not fit a historical scientist.
- has refined – present perfect; connects a past action to the present, which is odd for someone who is no longer alive.
- would refine – conditional or habitual; sounds hypothetical or like a repeated action, not a single factual achievement.
- refined – simple past; clearly and correctly states that Franklin completed this work in the past.
Therefore, the correct choice is "refined".