Question 132·Hard·Boundaries
Much of the current research on chronobiology focuses on circadian _____ earlier studies tended to treat daily fluctuations in behavior as mere anomalies.
Which choice completes the text so that it conforms to the conventions of Standard English?
For punctuation/boundary questions, first test whether the words before and after the blank can each stand alone as a sentence; if so, you are dealing with two independent clauses. Next, look at the relationship (contrast, cause, addition) and identify whether the connecting word is a coordinating conjunction (like "and," "but") or a conjunctive adverb (like "however," "therefore"). For conjunctive adverbs in the middle of a sentence, remember they need a strong boundary (semicolon or period) before them and typically a comma after them. Eliminate options that create run-ons, comma splices, or that fail to set off the transition word with appropriate punctuation.
Hints
Check if both sides are full sentences
Cover everything after the blank and read only the first part. Then cover everything before the blank and read only the second part. Ask yourself: can each part stand alone as a complete sentence?
Notice the repeated word in all choices
All choices use the word "however" in some form. Think about how you normally punctuate a word like "however" when it appears in the middle of a sentence to contrast two complete ideas.
Think about clause boundaries and commas
Since there are two complete clauses, you need punctuation strong enough to separate them and also to set off the transition word inside the second clause. Which option does both of these jobs?
Step-by-step Explanation
Identify the clauses on each side of the blank
Read the part before the blank: "Much of the current research on chronobiology focuses on circadian rhythms." This is a complete sentence (independent clause) with a subject and verb.
Now read the part after the blank: "earlier studies tended to treat daily fluctuations in behavior as mere anomalies." This is also a complete sentence with its own subject ("earlier studies") and verb ("tended").
So, the blank must correctly join two independent clauses.
Recognize the transition word and its function
All four answer choices use the word "however" in some form. "However" here is a conjunctive adverb that shows contrast between the two clauses:
- Current research focuses on circadian rhythms
- Earlier studies treated daily fluctuations as anomalies
Because "however" is connecting two complete sentences, we must use punctuation strong enough to separate them and correctly set off the transition word.
Recall the punctuation rule for conjunctive adverbs
When a conjunctive adverb like "however" connects two independent clauses in the middle of the sentence, the standard pattern is:
- A semicolon (or period) before the conjunctive adverb to end the first clause, and
- A comma after the conjunctive adverb at the start of the second clause.
So here, we need punctuation that provides:
- A clause boundary before "however" (stronger than just a comma or nothing), and
- A comma after "however" within the second clause.
Match the rule to the answer choices
Check each option:
- rhythms however → No punctuation before or after "however": this incorrectly creates a run-on and does not set off the transition.
- rhythms however, → There is still no punctuation before "however" to separate the two clauses, so it is still a run-on.
- rhythms; however → The semicolon before "however" correctly separates the clauses, but there is no comma after "however," which is required in this construction on the SAT.
- rhythms; however, → Has a semicolon before the transition word and a comma after it, correctly joining the two independent clauses and punctuating the conjunctive adverb.
Therefore, the correct answer is rhythms; however,.