By planting over fifteen thousand native seedlings across the degraded ______ initiative restored critical habitat for more than forty endangered...

Sentence Structure

• By planting over fifteen thousand native seedlings
• across the degraded hillsides (?) the
• initiative
  • restored critical habitat
    • for more than forty endangered species
  • and stabilized the watershed.

Understanding the Meaning

Let's start reading from the beginning:

'By planting over fifteen thousand native seedlings across the degraded hillsides'

This opening phrase tells us about a METHOD or action:

• Someone planted more than 15,000 native tree seedlings
• They planted them on hillsides that were degraded (damaged or deteriorated)

This is where we have the blank.

Let's look at the choices:

• We need to decide what punctuation (if any) comes after 'hillsides'
• The options are: semicolon, colon, opening parenthesis, or comma

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

'the initiative restored critical habitat for more than forty endangered species and stabilized the watershed'

Now we can see what this tells us:

• 'the initiative' - this is what took the action
• 'restored critical habitat for more than forty endangered species'
  • The result of planting those seedlings was bringing back habitat that endangered species need
• 'and stabilized the watershed'
  • Another result: it helped protect the water drainage system in that area

So the complete picture is:

• The opening phrase describes HOW the work was done (by planting seedlings)
• The rest of the sentence tells us WHAT happened (the initiative restored habitat and stabilized the watershed)

What do we notice about the structure here?

• The first part - 'By planting over fifteen thousand native seedlings across the degraded hillsides' - is an introductory phrase
  • It sets the scene and tells us the method
  • It can't stand alone as a complete sentence
• The second part - 'the initiative restored critical habitat for more than forty endangered species and stabilized the watershed' - is a complete thought
  • It has a subject ('the initiative')
  • It has actions ('restored' and 'stabilized')
  • It could stand alone as its own sentence

When you have an introductory phrase like this that provides context, followed by the main complete thought, you separate them with a comma.

So we need Choice D: hillsides, the

GRAMMAR CONCEPT APPLIED

Using Commas with Introductory Phrases

When a sentence begins with an introductory element - a phrase or clause that provides background, context, or describes how/when/where something happens - that introductory element should be separated from the main clause with a comma.

The Pattern:

• Introductory phrase (provides context) + COMMA + main clause (complete thought)

Example 1:

• Without context: The company announced record profits.
• With introductory phrase: After years of restructuring, the company announced record profits.
• 'After years of restructuring' = introductory phrase (sets the time context)
• Comma separates it from the main clause

Example 2:

• Without context: The experiment yielded surprising results.
• With introductory phrase: By carefully controlling all variables, the experiment yielded surprising results.
• 'By carefully controlling all variables' = introductory phrase (describes the method)
• Comma separates it from the main clause

In our question:

• By planting over fifteen thousand native seedlings across the degraded hillsides, the initiative restored critical habitat for more than forty endangered species and stabilized the watershed.
• 'By planting over fifteen thousand native seedlings across the degraded hillsides' = introductory phrase describing the method
• COMMA needed to separate from main clause
• 'the initiative restored critical habitat...' = main clause with subject and verbs