The Kuiper Belt, located beyond Neptune's orbit, contains thousands of icy objects that offer clues about the early solar system....

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

• The Kuiper Belt,
• located beyond Neptune's orbit,
• contains thousands of icy objects
• that offer clues about the early solar system.

• Among the belt's most intriguing discoveries
• [?] Arrokoth,
• a pristine body
• that revealed how planetesimals formed billions of years ago.

• Where [?] = was/were/have been/are

Understanding the Meaning

Let's start reading:

The first sentence gives us context:

• 'The Kuiper Belt, located beyond Neptune's orbit'
  • tells us where this region is in space
• 'contains thousands of icy objects that offer clues about the early solar system'
  • tells us what's in this belt and why it matters to scientists

Now the second sentence:

• 'Among the belt's most intriguing discoveries...'
  • This is telling us about something found in the Kuiper Belt

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

• was (singular, past)
• were (plural, past)
• have been (plural, present perfect)
• are (plural, present)

So we're deciding: singular or plural? And what tense?

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

• '_____ Arrokoth, a pristine body that revealed how planetesimals formed billions of years ago.'

Now let's really understand what this structure is telling us:

• 'Arrokoth'
  • is the name of a specific object discovered in the Kuiper Belt
  • it's described as 'a pristine body' - meaning it's been preserved in its original state

• 'that revealed how planetesimals formed billions of years ago'
  • tells us what scientists learned from studying Arrokoth
  • this discovery happened in the past

What do we notice about the structure here?

• The sentence is inverted - it starts with 'Among the belt's most intriguing discoveries'
  • But that's just a prepositional phrase setting the scene

• The actual subject comes AFTER the blank: Arrokoth
  • If we rearranged it normally, we'd say: "Arrokoth was among the belt's most intriguing discoveries"

• Arrokoth is singular (it's one specific object)
  • So we need a singular verb

• The context is past tense
  • The discovery happened in the past
  • The sentence describes what Arrokoth "revealed" (past tense)

So we need: was - singular and past tense, matching both the subject "Arrokoth" and the past context of the discovery.

GRAMMAR CONCEPT APPLIED

Subject-Verb Agreement in Inverted Sentences

Sometimes sentences are inverted - they start with a prepositional phrase, and the subject comes AFTER the verb instead of before it. This structure can trick you if you're not careful. The key is to identify the true subject and make the verb agree with it.

Normal word order:

• Subject + Verb + Prepositional Phrase
• "Arrokoth was among the belt's most intriguing discoveries"
  • Subject: Arrokoth (singular)
  • Verb: was (singular)

Inverted word order:

• Prepositional Phrase + Verb + Subject
• "Among the belt's most intriguing discoveries was Arrokoth"
  • The phrase "Among the belt's most intriguing discoveries" comes first
  • But "Arrokoth" is still the subject
  • The verb "was" must agree with "Arrokoth" (singular)

How to handle these questions:

1. Identify when a sentence starts with a prepositional phrase (often starting with words like "among," "between," "in," "at," "behind")
2. Look for the true subject - it will come after the verb
3. Ignore any plural nouns in the prepositional phrase (like "discoveries") - they're not the subject
4. Make the verb agree with the actual subject

In this question:

• "Among the belt's most intriguing discoveries" = prepositional phrase (not the subject)
• "Arrokoth" = true subject (singular)
• Therefore: "was" (singular verb) is correct