Question 249·Hard·Form, Structure, and Sense
Tracking dozens of migratory hawks across the Atlantic, researcher Luisa Moreno noticed that several birds drifted far south of their usual routes. Hoping to understand the cause of this deviation, ______ by installing temperature-sensitive transmitters on the hawks' legs.
Which choice completes the text so that it conforms to the conventions of Standard English?
For modifier-placement questions, first locate any introductory phrase (like "Hoping to understand the cause of this deviation") and immediately ask who or what it is describing. The noun right after the comma must be the logical doer of that action or state. Eliminate any answer that makes an inanimate thing or the wrong noun perform the action of the modifier, or that leaves out the true actor. Among remaining choices, prefer clear, active constructions that form a complete, logical sentence.
Hints
Focus on the introductory phrase
Look closely at the phrase before the comma: "Hoping to understand the cause of this deviation." Ask yourself: who in the sentence actually has this hope?
Match the modifier to the right subject
In English, a phrase like "Hoping to understand..." must describe the noun that comes right after the comma. Which answer choice makes that noun a person who can reasonably be "hoping"?
Check for logical meaning
Try reading the sentence with each choice: does it accidentally make a study, a hawk, or a transmitter "do" the hoping? Cross out any choice where the meaning becomes illogical.
Confirm a complete, clear clause
Make sure the words in the blank form a full main clause (subject + verb) that can logically be followed by "by installing temperature-sensitive transmitters on the hawks' legs."
Step-by-step Explanation
Identify the sentence structure
The sentence begins with an introductory phrase: "Hoping to understand the cause of this deviation," followed by a comma and a blank. That introductory phrase is a modifier (a participial phrase) and must describe the noun that comes right after the comma. After the blank, the sentence continues with "by installing temperature-sensitive transmitters on the hawks' legs," which describes how the action in the blank was carried out.
Decide who is doing the "hoping"
Ask: Who is actually "hoping to understand the cause of this deviation"? It is the researcher, Luisa Moreno—not the hawks, not the study, and not the transmitters. Therefore, the noun immediately after the comma (the subject of the main clause) should logically refer to Moreno, the person with the goal and intention.
Check for a clear, active main clause
The blank must form a full, grammatically complete main clause (subject + verb) that can be modified by both the introductory phrase and the "by installing…" phrase. That clause should:
- Have the correct doer of the action as the subject (the researcher)
- Be in clear, active voice
- Connect logically to "by installing temperature-sensitive transmitters..." (this phrase tells how the action in the blank was carried out)
Eliminate any choice where the subject after the comma is an inanimate thing "doing the hoping" or where the sentence becomes awkward or illogical.
Select the choice that fits grammar and meaning
Only choice A) "Moreno designed a follow-up study" places the actual person (Moreno) right after the comma as the subject, creates a clear and complete clause, and logically links to "by installing temperature-sensitive transmitters on the hawks' legs." The full sentence reads: "Hoping to understand the cause of this deviation, Moreno designed a follow-up study by installing temperature-sensitive transmitters on the hawks' legs." This is logical, grammatical, and follows standard English conventions.