Earth is not a perfect sphere. Due to the ________ gravitational pull, Earth bulges out on the sides closest to...

SOLUTION

Let's begin by understanding the meaning of this sentence. We'll use our understanding of pause points and segment the sentence as shown - understanding and assimilating the meaning of each segment bit by bit!

Sentence Structure

Sentence 1:

• Earth is not a perfect sphere.

Sentence 2:

• Due to the (?) gravitational pull,
• Earth bulges out
  • on the sides
    • closest to and farthest from the Moon.

Sentence 3:

• This distorting pull is known as a tidal force,
• and it is responsible for the changes
  • in water levels
    • that are called high and low tides.

Understanding the Meaning

The passage starts with a simple fact:

• "Earth is not a perfect sphere."

Then it explains why:

• "Due to the ______ gravitational pull,"

Now here's where we need to fill in the blank. The phrase is "the ______ gravitational pull."

Let's look at our choices:

• A. Moon's
• B. Moons
• C. Moons'
• D. Moon

What do we notice here? We're talking about a gravitational pull, and we need to show whose pull it is - where it comes from.

• The gravitational pull belongs to the Moon.
• This is what we call a possessive relationship -
  • one thing (the pull) belongs to or comes from another thing (the Moon).

• To show this possessive relationship, we need an apostrophe.

• Since Earth has one Moon (not multiple moons),
  • we need the singular possessive form: Moon's

So we need Choice A: Moon's

Now let's read the rest to see the complete picture:

• "Earth bulges out on the sides closest to and farthest from the Moon."

This confirms we're talking about one Moon - Earth's moon - and explaining how its gravitational force affects Earth's shape.

The final sentence wraps it up:

• "This distorting pull is known as a tidal force, and it is responsible for the changes in water levels that are called high and low tides."

So the passage is explaining how the Moon's gravitational pull causes Earth to bulge, which creates tides.

GRAMMAR CONCEPT APPLIED

Showing Possession with Singular Nouns

When you want to show that something belongs to or is associated with a singular noun (one thing), you create the possessive form by adding an apostrophe and 's' to the noun:

Pattern: Noun + 's + thing that belongs to it

Examples:

• The cat's tail = the tail that belongs to the cat
  • cat (one cat) + 's + tail

• The student's notebook = the notebook that belongs to the student
  • student (one student) + 's + notebook

• The Moon's gravitational pull = the gravitational pull that belongs to/comes from the Moon
  • Moon (one moon) + 's + gravitational pull

This is different from:

• Plural (no possession): cats, students, moons (just means more than one)
• Plural possessive: cats', students', moons' (means something belongs to multiple things)

In this question, we need to show that the gravitational pull belongs to one Moon (Earth's moon), so we use Moon's - the singular possessive form (called a possessive noun in grammar terms).