Question

which sentence is correct?
\the professor is knowledgeable about woodpecker habitats,\ mrs. blackburn said.
the professor is knowledgeable about woodpecker habitats. mrs. blackburn said.
\the professor is knowledgeable about woodpecker habitats.\ mrs. blackburn said.
the professor is knowledgeable about woodpecker habitats, mrs. blackburn said.

Explanation:

To determine the correct sentence, we analyze the rules of direct speech punctuation:

1. When directly quoting someone, the quoted sentence should be enclosed in quotation marks.
2. If the quote ends with a punctuation mark (like a period or comma) and is followed by the speaker's name, the punctuation inside the quotes depends on the context. In the case of a declarative sentence being quoted, the quote should end with a period inside the quotes, and then the speaker's statement follows. However, in the first option, the comma inside the quotes is used correctly when the quote is a part of the sentence introducing the speaker. Wait, no—let's re - examine:

• For the first option: "The professor is knowledgeable about woodpecker habitats," Mrs. Blackburn said. This is correct because when the quote is a complete thought but the sentence structure has the speaker's name following, a comma is used inside the quotes to separate the quote from the speaker's attribution.
• The second option: The professor is knowledgeable about woodpecker habitats. Mrs. Blackburn said. This is incorrect because the first sentence is a complete statement, and then "Mrs. Blackburn said" is a separate sentence, but it should be related to the quote. It's not a proper way to present a direct quote.
• The third option: "The professor is knowledgeable about woodpecker habitats." Mrs. Blackburn said. This is incorrect because after a quoted sentence that ends with a period, the next part "Mrs. Blackburn said" should be connected more properly. Usually, if the quote is a complete sentence and the speaker's name follows, we use a comma after the closing quote, not a period.
• The fourth option: The professor is knowledgeable about woodpecker habitats, Mrs. Blackburn said. This is incorrect because it's a run - on - like structure. It should be a direct quote with quotation marks if it's Mrs. Blackburn's words.

So the correct sentence is the first one: "The professor is knowledgeable about woodpecker habitats," Mrs. Blackburn said.

Answer:

"The professor is knowledgeable about woodpecker habitats," Mrs. Blackburn said.