In 2016, engineer Vanessa Galvez oversaw the installation of 164 bioswales, vegetated channels designed to absorb and divert stormwater, along...
GMAT Standard English Conventions : (Grammar) Questions
In 2016, engineer Vanessa Galvez oversaw the installation of 164 bioswales, vegetated channels designed to absorb and divert stormwater, along the streets of Queens, New York. By reducing the runoff flowing into city sewers, ______
Which choice completes the text so that it conforms to the conventions of Standard English?
the mitigation of both street flooding and the resulting pollution of nearby waterways has been achieved by bioswales.
the bioswales have mitigated both street flooding and the resulting pollution of nearby waterways.
the bioswales' mitigation of both street flooding and the resulting pollution of nearby waterways has been achieved.
both street flooding and the resulting pollution of nearby waterways have been mitigated by bioswales.
Let's begin by understanding the meaning of this sentence. We'll use our understanding of pause points and segment the sentence as shown - understanding and assimilating the meaning of each segment bit by bit!
Sentence Structure
- In 2016,
- engineer Vanessa Galvez
- oversaw the installation of 164 bioswales,
- vegetated channels
- designed to absorb and divert stormwater,
- vegetated channels
- along the streets of Queens, New York.
- oversaw the installation of 164 bioswales,
- engineer Vanessa Galvez
- By reducing the runoff
- flowing into city sewers,
- [?] (what follows?)
Understanding the Meaning
Let's start by understanding the context from the first sentence:
- 'In 2016, engineer Vanessa Galvez oversaw the installation of 164 bioswales'
- Bioswales were installed in 2016
- They're described as 'vegetated channels designed to absorb and divert stormwater'
- So bioswales are these planted channels that handle rainwater
- 'along the streets of Queens, New York'
- Tells us where they were installed
Now the second sentence begins:
- 'By reducing the runoff flowing into city sewers,'
- This phrase tells us HOW something is accomplished
- What's doing the reducing? The bioswales - they reduce the runoff
This is where we have the blank.
Let's look at the choices:
- They differ in what comes right after the comma
- A and C have "the mitigation" as the subject
- B has "the bioswales" as the subject
- D has "street flooding and pollution" as the subject
Here's what we notice about the structure:
- The phrase "By reducing the runoff..." describes HOW something is being accomplished
- This type of phrase needs to connect logically to whatever comes after the comma
- Specifically, whatever comes after should be WHAT is doing the reducing
- What's doing the reducing? The bioswales!
- The bioswales are reducing the runoff
- So "the bioswales" needs to be the subject of what follows
The correct answer is Choice B: "the bioswales have mitigated both street flooding and the resulting pollution of nearby waterways."
Why? Because the bioswales are the ones doing the reducing, so they need to be the subject of the main clause. This makes the sentence logical: "By reducing the runoff, the bioswales have mitigated street flooding and pollution."
GRAMMAR CONCEPT APPLIED
Connecting Introductory Phrases to What Follows
When a sentence begins with a descriptive phrase (called an introductory modifier in grammar terms), especially one starting with "By [verb-ing]," that phrase must logically connect to the subject that comes after the comma. The implied subject in the phrase must match the explicit subject of the main clause.
The Pattern:
- Introductory phrase: By reducing the runoff... [WHO is reducing? The bioswales]
- Main clause subject must match: the bioswales have mitigated... ✓
Why this matters:
When the subjects don't match, you create what's called a "dangling modifier" - a phrase that doesn't logically connect to what it's supposed to describe.
Examples:
✓ Correct: By studying every night, Maria improved her grades.
- "By studying" → Maria is the one studying → Maria is the subject ✓
✗ Incorrect: By studying every night, her grades improved.
- "By studying" → who is studying? → "grades" can't study ✗
- The phrase dangles without a logical connection
In this question:
- "By reducing the runoff" → bioswales are reducing → "the bioswales" must be the subject
- Choice B correctly makes "the bioswales" the subject
- The other choices put different subjects (mitigation, flooding) that can't logically be "reducing" anything
the mitigation of both street flooding and the resulting pollution of nearby waterways has been achieved by bioswales.
✗ Incorrect
- The subject here is "the mitigation" (the abstract concept)
- But "mitigation" can't be the thing that's reducing runoff - bioswales reduce runoff
- This creates an illogical connection: the opening phrase doesn't match what follows
- The phrase "By reducing..." dangles without properly connecting to the subject
the bioswales have mitigated both street flooding and the resulting pollution of nearby waterways.
✓ Correct
- Correct as explained in the solution above.
the bioswales' mitigation of both street flooding and the resulting pollution of nearby waterways has been achieved.
✗ Incorrect
- Similar problem to A - the subject is still "mitigation" (just in possessive form)
- "Mitigation" isn't what's reducing the runoff; the bioswales are
- This also creates that dangling, illogical connection
- Additionally, it's unnecessarily wordy and passive
both street flooding and the resulting pollution of nearby waterways have been mitigated by bioswales.
✗ Incorrect
- The subject here is "street flooding and pollution"
- But flooding and pollution aren't reducing runoff - they're the problems being solved!
- This creates an illogical statement: it would suggest that flooding is somehow reducing runoff
- The introductory phrase doesn't connect properly to what follows