Question 24·200 Super-Hard SAT Reading Questions·Standard English Conventions
When paleobotanist Lena Okafor revisited a museum drawer, she expected its specimens to have been described already. One shale fragment at first seemed ______ the feeding marks on it crossed intact leaf veins instead of following cracks in the shale, Okafor ruled out damage that had occurred after fossilization.
Which choice completes the text so that it conforms to the conventions of Standard English?
For difficult boundary questions, identify every main clause before evaluating the punctuation. If a unit begins with a subordinating word such as “because,” continue reading to see whether that dependent clause introduces a main clause; the full unit may still be independent and therefore require a comma plus a coordinating conjunction when joined to another independent clause.
Hints
Locate the first complete thought
Determine whether the words before the blank contain both a subject and a finite verb and can stand as a complete sentence.
Read beyond the subordinating word
Do not classify everything after the blank as dependent merely because it begins with “because.” Identify the main clause that follows the introductory dependent clause.
Check the clause connection
When a coordinating conjunction joins two independent sentence units, check whether a comma is needed before the conjunction.
Step-by-step Explanation
Identify the first independent clause
“One shale fragment at first seemed unremarkable” contains a subject and verb and expresses a complete thought, so it is an independent clause.
Analyze the material after the blank
The clause beginning with “because” is dependent, but it is followed by the independent clause “Okafor ruled out damage that had occurred after fossilization.” Together, those parts form a complete complex sentence unit: “because the feeding marks on it crossed intact leaf veins instead of following cracks in the shale, Okafor ruled out damage that had occurred after fossilization.”
Join the independent clauses
The first independent clause and the complete complex sentence unit must be joined correctly. A comma followed by the coordinating conjunction “but” creates the required boundary: “unremarkable, but because.”