PSAT Writing and Language Question 313: Answer and Explanation

Question: 313

• A. NO CHANGE
• B. ago so scientists
• C. ago, scientists
• D. ago. Scientists

Correct Answer: D

Explanation:

Difficulty: Easy

Category: Sentence Structure: The Basics

Getting to the Answer: A sentence is a run-on if it has two improperly joined independent clauses that could be stand-alone sentences. The parts of the sentence before and after the underline are both independent clauses that express complete thoughts. Both a comma and a FANBOYS conjunction are required when combining two independent clauses. Eliminate (A) and (B) because they are missing the comma, and eliminate (C) because it is missing a FANBOYS conjunction. Choice (D) correctly divides the two independent clauses into two separate sentences.