Question 6·Hard·Boundaries
A journalist investigating urban farming observed that rooftop gardens reduce a building’s energy ______ providing habitats for pollinators, improving air quality, and cultivating a sense of community among residents.
Which choice completes the text so that it conforms to the conventions of Standard English?
For boundaries questions, first determine whether the text after the blank is an independent clause. If it is, consider a period, semicolon, or comma + coordinating conjunction. If it is not independent (for example, it starts with an verb like "providing"), you usually need a comma to attach that phrase to the main clause, and you should eliminate semicolons and periods.
Hints
Look at the first word after the blank
The next word is "providing." That usually signals an added phrase (not a new full sentence).
Check for a subject after the blank
Ask whether the words after the blank have their own subject (like "they"). If not, you probably shouldn’t use a semicolon or a period.
Match the punctuation to the structure
A comma can attach an phrase to a complete clause. A semicolon needs a complete clause on both sides.
Step-by-step Explanation
Identify what comes after the blank
After the blank, the sentence continues with providing, improving, and cultivating. These are verbs forming a participial phrase that adds extra information about what rooftop gardens do.
Decide whether the material after the blank is an independent clause
An independent clause needs (at minimum) a subject and a finite verb (e.g., "they provide").
"providing habitats for pollinators, improving air quality, and cultivating..." does not have its own subject or finite verb, so it is not an independent clause.
Choose the boundary that correctly introduces an elaborating phrase
Because the sentence begins with a complete independent clause ("...rooftop gardens reduce a building’s energy consumption") and then adds an elaborating participial phrase, the correct convention is to use a comma to attach that phrase to the main clause.
Confirm by testing each option in the sentence
- With a comma, the sentence correctly reads: "...reduce a building’s energy consumption, providing habitats..., improving..., and cultivating..."
- A semicolon or period would incorrectly separate the main clause from a non-independent fragment.
- A colon is not appropriate here because what follows is not a clear explanation/restatement or a properly introduced list.
Therefore, the correct choice is consumption,.