Human-made (synthetic) fibers used in clothes and many other consumer products are more durable than most natural plant ______ the manufacture of synthetic fibers requires toxic chemical solvents that can pollute air and water.
Which choice completes the text so that it conforms to the conventions of Standard English?
Explanation
Context: The sentence has two independent clauses connected by contrast: "synthetic fibers are more durable than most natural plant fibers" and "the manufacture of synthetic fibers requires toxic chemical solvents that can pollute air and water." The word "but" introduces the contrasting clause.
Answer: D) fibers, but
Why? Two independent clauses joined by the coordinating conjunction "but" require a comma before "but." "Fibers, but" correctly applies this FANBOYS rule.
Traps:
- A) fibers, → comma splice; a comma alone (without the conjunction) cannot join two independent clauses
- B) fibers but → missing the required comma before "but" when joining two independent clauses
- C) fibers → run-on; no punctuation or conjunction between the two independent clauses