Marine biologist Dr. Sarah Chen spent fifteen years studying coral reef ecosystems in the Caribbean. Her groundbreaking research began in...

Sentence Structure

• Marine biologist Dr. Sarah Chen spent fifteen years studying coral reef ecosystems in the Caribbean.
• Her groundbreaking research began in the waters off Jamaica [?, and]
• in 2023 her findings were published in a leading scientific journal.

Understanding the Meaning

Let's start from the beginning:

• 'Marine biologist Dr. Sarah Chen spent fifteen years studying coral reef ecosystems in the Caribbean.'
  • This is straightforward - Dr. Chen dedicated 15 years to researching Caribbean coral reefs.

Now the second sentence:

• 'Her groundbreaking research began in the waters off Jamaica...'
  • This tells us where specifically her important research started.

This is where we have the blank. Let's look at the choices:

• A: Jamaica, and
• B: Jamaica,
• C: Jamaica and
• D: Jamaica (nothing)

To see what works here, let's read the rest of the sentence and understand what it's saying!

The sentence continues: 'in 2023 her findings were published in a leading scientific journal.'

Now let's understand what we have here:

• First part: 'Her groundbreaking research began in the waters off Jamaica'
  • Subject: 'Her groundbreaking research'
  • Action: 'began'
  • Where: 'in the waters off Jamaica'
  • This expresses a complete thought - it can stand alone as its own sentence.

• Second part: 'in 2023 her findings were published in a leading scientific journal'
  • Subject: 'her findings'
  • Action: 'were published'
  • When: 'in 2023'
  • Where: 'in a leading scientific journal'
  • This also expresses a complete thought - it can stand alone too.

What do we notice about the structure here?

• We have TWO complete thoughts that each could be separate sentences.
• These two complete thoughts need to be connected properly.
• In Standard English, you cannot just:
  • Put two complete thoughts together with nothing between them (run-on)
  • Connect them with only a comma (comma splice)
• You need to connect complete thoughts with:
  • A comma + a connecting word like 'and'
  • OR
  • A semicolon
  • OR
  • Make them separate sentences with a period

The correct answer is Choice A: Jamaica, and

This gives us the comma plus the connecting word "and" that we need to properly join these two complete thoughts. The sentence flows naturally: her research began in Jamaica's waters, AND in 2023 her findings were published.

GRAMMAR CONCEPT APPLIED

Connecting Two Complete Thoughts

When you want to join two complete thoughts (called independent clauses in grammar terms) - meaning two parts that each have their own subject and verb and could stand alone as sentences - you need to connect them properly. You cannot just put them together with nothing or with only a comma.

The standard ways to connect two complete thoughts:

Pattern 1: Comma + Coordinating Conjunction

• Complete thought 1: The experiment succeeded
• Complete thought 2: the team celebrated their breakthrough
• Correct: The experiment succeeded, and the team celebrated their breakthrough
• The comma + "and" properly connects the two thoughts
• Common coordinating conjunctions: and, but, or, so, yet, for, nor

Pattern 2: Semicolon (when thoughts are closely related)

• Correct: The experiment succeeded; the team celebrated their breakthrough

Pattern 3: Period (make them separate sentences)

• Correct: The experiment succeeded. The team celebrated their breakthrough.

In our question:

• Complete thought 1: Her groundbreaking research began in the waters off Jamaica
• Complete thought 2: in 2023 her findings were published in a leading scientific journal
• Correct connection: Her groundbreaking research began in the waters off Jamaica, and in 2023 her findings were published in a leading scientific journal.

The comma plus "and" creates the proper bridge between these two complete thoughts, allowing them to flow naturally as one sentence while respecting the grammatical structure of each part.