Question 111·Hard·Form, Structure, and Sense
After filming thousands of hummingbirds in flight, _____
Which choice completes the text so that it conforms to the conventions of Standard English?
For sentence-completion questions with an introductory phrase (often starting with words like “After,” “When,” “Although,” or an -ing verb), first locate the noun or subject that should logically be described by that phrase, and make sure it appears immediately after the comma—this avoids dangling modifiers. Then, among the grammatically acceptable options, choose the one that is clearest and most concise, preferring active voice (“X discovered…”) over clunky, passive, or overly wordy alternatives (“it was discovered by X…”).
Hints
Focus on the introductory phrase
Look closely at the phrase “After filming thousands of hummingbirds in flight, …”. Ask yourself: who is doing the filming, and where should that person or group appear in the sentence?
Check the subject after the comma
The noun or pronoun right after the comma should be the one that did the filming. Which choices make a nonhuman thing (like “footage” or “evidence”) or a vague “it” the subject?
Look for clear and concise wording
Between options that might be grammatically possible, prefer the one that is active and straightforward rather than wordy or awkwardly passive (for example, using “it was discovered by …”).
Step-by-step Explanation
Understand the sentence structure
The sentence begins with an introductory phrase: “After filming thousands of hummingbirds in flight, ____.”
This kind of phrase is a modifier: it describes who did the filming and what happened after. In standard English, the noun or subject that the phrase modifies should come immediately after the comma.
Match the modifier to a logical subject
Ask: Who filmed thousands of hummingbirds in flight? Logically, it must be people, such as researchers, not an abstract thing like footage or evidence.
So the word or phrase right after the comma must refer to those people, not to “footage,” “evidence,” or a vague “it.” If the subject after the comma is something that cannot do the filming, the modifier is “dangling” (attached to the wrong thing) and the sentence is incorrect.
Eliminate dangling and awkward constructions
Go through the choices and check:
- Does the subject right after the comma clearly refer to the people who filmed the birds?
- Is the sentence clear and not unnecessarily wordy (for example, avoiding clunky phrases like “it was discovered by the researchers”)?
Cross out any option where:
- The subject is nonhuman (like “footage” or “evidence”) that would wrongly seem to be doing the filming, or
- The people are only in a prepositional phrase (like “by the researchers”), which still leaves the modifier attached to a different grammatical subject.
Choose the clear, active, and grammatical completion
Only one option places the people (the researchers) as the grammatical subject right after the comma and uses a clear, active verb:
Correct answer: “the researchers discovered that the birds generate lift not only on the downstroke but also on the upstroke of their wings.”
This makes it clear that the researchers filmed the hummingbirds and then discovered how the birds generate lift, so it follows the conventions of Standard English.