In the following sentence, fill in the blank with the most appropriate word: "The professor _______________ over just one point for a full two hours."

Introduction / Context:
This vocabulary and usage question asks you to choose the verb that best fits the sentence: "The professor _______________ over just one point for a full two hours." The key is to understand the meaning suggested by "over just one point" and the duration of "a full two hours". This hints at careful, extended consideration of a particular issue.

Given Data / Assumptions:

• Subject: "The professor".
• Object phrase: "over just one point".
• Time expression: "for a full two hours".
• Options: "deliberated", "mentioned", "conversed", "stated", "argued".
• We assume the professor was thinking or talking about that one point for a long period.

Concept / Approach:
The verb must combine naturally with the preposition "over" and express prolonged thinking or discussion about a single issue. "Deliberate over" means to think carefully or discuss thoroughly before reaching a decision. It is often used for extended, serious consideration. This matches both "over one point" and "for a full two hours". The other verbs either do not typically take "over" in this sense or do not imply lengthy, careful consideration.

Step-by-Step Solution:
Step 1: Focus on the phrase "over just one point" and note that verbs like "deliberate over" or "argue over" are possible collocations.Step 2: Consider the time span "for a full two hours", which implies sustained effort rather than a brief action like "mention" or "state".Step 3: "Deliberated over" means thought about and discussed carefully, fitting both the preposition and the time frame.Step 4: "Argued over" would suggest conflict with someone else, but the sentence does not mention any opponent or debate.Step 5: Therefore, "deliberated" is the most appropriate choice, giving "The professor deliberated over just one point for a full two hours."

Verification / Alternative check:
Read the full sentence after inserting "deliberated": "The professor deliberated over just one point for a full two hours." This sounds natural and clearly conveys that the professor spent a long time analysing or discussing that single point. If you replace it with "mentioned", the sentence becomes illogical: "mentioned over just one point" is not a standard phrase and does not justify two full hours. "Conversed over" and "stated over" are also unnatural collocations.

Why Other Options Are Wrong:

• mentioned: Means "referred to briefly", which contradicts the idea of spending "a full two hours" on one point.
• conversed: We say "conversed with someone", not "conversed over one point"; the preposition and object are wrong.
• stated: Means "said something clearly", usually in a simple, one time act; it does not fit with "over one point for two hours".
• argued: "Argued over" suggests a dispute with someone else, but the sentence does not indicate any argument; it focuses on the professor's extended focus on a point.

Common Pitfalls:
Students may pick verbs solely based on general familiarity without checking prepositional patterns like "deliberate over". Always consider the full context, including time expressions and the prepositions that naturally follow each verb. Learning typical verb + preposition combinations (collocations) is crucial for scoring well in such questions.

Final Answer:
The correct verb is deliberated, giving the sentence: "The professor deliberated over just one point for a full two hours."