Question 124·Easy·Boundaries
Bark beetles are tiny insects that infest conifer trees. They lay their eggs beneath the bark, where the larvae feed on the tree's nutrient-rich tissues, disrupting the flow of water and sap. If left unchecked, a severe infestation can kill a mature tree _____ just a few months.
Which choice completes the text so that it conforms to the conventions of Standard English?
For SAT punctuation (boundaries) questions, first identify whether the words before and after the punctuation form complete sentences (independent clauses). Strong punctuation like semicolons and dashes should only be used between independent clauses or to set off clear interruptions. Avoid inserting commas or other punctuation inside tight units like prepositional phrases (a preposition plus its object). When all choices share the same words but differ in punctuation, your main task is to decide whether any separation is needed at all; if not, choose the version with no extra punctuation.
Hints
Look at what comes after the blank
Focus on the words after the blank: "just a few months." Ask yourself: is this a full sentence or just a phrase describing when something happens?
Think about when strong punctuation is used
Semicolons and dashes usually separate bigger units of meaning, like complete sentences or clear interruptions. Do you see a complete sentence or an interrupting idea after the blank?
Consider the role of the word before the punctuation
Notice that all choices start with the same word followed by different punctuation. That word introduces a time phrase. Should anything come between that word and the time phrase it introduces?
Test the sentence out loud
Read the sentence with a natural speaking rhythm. Does it sound natural to pause strongly right after the small word before "just a few months," or should the words flow together without a break?
Step-by-step Explanation
Understand the sentence meaning
Read the full sentence:
"If left unchecked, a severe infestation can kill a mature tree _____ just a few months."
The idea is that a severe infestation can kill a tree within a short time period—specifically, within just a few months.
Identify what kind of phrase follows the blank
Look at the words after the blank: "just a few months."
This is a time phrase telling when or how quickly the tree can be killed. It is not a complete sentence (it has no subject or verb). It needs to be linked smoothly to what comes before it.
Notice that all choices use the same word but different punctuation
Each option is the same word plus different punctuation:
- A) in;
- B) in—
- C) in
- D) in,
So the question is not about vocabulary, but about whether punctuation is needed between this word and "just a few months."
Decide if strong punctuation is appropriate here
A semicolon or a dash is used to create a strong break:
- A semicolon must go between two complete sentences (independent clauses).
- A dash usually sets off an added or interrupting idea.
Here, what follows is only "just a few months," which is not a complete sentence and is not an interruption—it's an essential time phrase that completes the idea. So strong punctuation (semicolon or dash) would be grammatically wrong.
Check whether any comma is appropriate
A comma would create a pause: "kill a mature tree in, just a few months."
This would separate the preposition from its phrase ("in" from "just a few months"), which is not correct. The preposition should be directly followed by its object without a comma in between.
Choose the option with no unnecessary break
Because the time phrase "just a few months" should be connected directly to the preposition with no punctuation in between, the sentence should read:
"If left unchecked, a severe infestation can kill a mature tree in just a few months."
The only option that fits this correctly is C) in.