Launched in 1990, the Hubble Space Telescope has revolutionized our understanding of the cosmos with its unprecedented views of distant...

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:

• Launched in 1990,
  • the Hubble Space Telescope
    • has revolutionized our understanding of the cosmos
      • with its unprecedented views
        • of distant galaxies and nebulae.

Sentence 2:

• Despite its groundbreaking achievements,
  • few people
    • realize
      • that [?] nearly abandoned
        • as a failed mission
          • after engineers discovered a flaw
            • in its primary mirror
            • shortly after deployment.

Understanding the Meaning

Let's start reading from the beginning:

The first sentence tells us:

• 'Launched in 1990, the Hubble Space Telescope has revolutionized our understanding of the cosmos with its unprecedented views of distant galaxies and nebulae.'
  • This establishes our main subject: the Hubble Space Telescope
  • It's telling us what this telescope has accomplished

Now the second sentence begins:

• 'Despite its groundbreaking achievements, few people realize that...'
  • The 'its' refers back to the Hubble Space Telescope
  • Now we're about to learn something most people don't know

This is where we have the blank.

Let's look at the choices:

1. one was
2. they were
3. it was
4. both were

These choices are giving us different pronouns (one, they, it, both) paired with verbs (was, were). To see what works here, let's read the rest of the sentence and understand what it's saying!

The complete clause reads:

• 'that ______ nearly abandoned as a failed mission after engineers discovered a flaw in its primary mirror shortly after deployment.'

Now let's understand what this is telling us:

• Something was 'nearly abandoned as a failed mission'
  • This is the main point - something almost got abandoned
  • 'As a failed mission' tells us why it would have been abandoned
• 'after engineers discovered a flaw in its primary mirror'
  • This explains when and why the abandonment was considered
  • 'Its' refers to the telescope's mirror
• 'shortly after deployment'
  • This happened right after the telescope was launched

What do we notice?

• The blank needs to refer back to what was nearly abandoned
  • Looking at the context, what was nearly abandoned? The Hubble Space Telescope
  • The telescope is singular and it's a thing (not a person)
• We need a pronoun that refers to 'the Hubble Space Telescope'
  • The telescope is singular
  • It's an object, not a person
  • The natural pronoun is 'it'
• We need the matching verb form
  • Since we're talking about something singular, we need 'was'
  • This is past tense (talking about what happened after 1990)

So we need: it was

The correct answer is C.

GRAMMAR CONCEPT APPLIED

Pronoun Agreement: Matching Pronouns to Their Antecedents

A pronoun must match its antecedent (the noun it refers to) in number - both must be singular or both must be plural. The pronoun must also be appropriate for what it's referring to (called pronoun-antecedent agreement in grammar terms).

The Pattern:

For singular antecedents (one thing):

• Antecedent: The telescope
• Pronoun: it
• Example: "The telescope was launched. It was nearly abandoned."

For plural antecedents (multiple things):

• Antecedent: The telescopes
• Pronoun: they
• Example: "The telescopes were launched. They were nearly abandoned."

Choosing the right pronoun:

• Use "it" for singular inanimate objects or animals
• Use "one" for generic references or when selecting from a group
• Use "they" for plural items
• Use "both" when specifically referring to two items

In this question:

• Antecedent: "the Hubble Space Telescope" (singular, inanimate object)
• Correct pronoun: "it"
• Correct verb: "was" (singular past tense)
• Complete answer: "it was nearly abandoned"

The key is identifying what noun the pronoun refers back to and making sure they match in number.