The James Webb Space Telescope captured images of the galaxy cluster SMACS 0723 in unprecedented detail, revealing thousands of previously...

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 James Webb Space Telescope
  • captured images
    • of the galaxy cluster SMACS 0723
    • in unprecedented detail,
  • revealing thousands
    • of previously unseen celestial objects [?]
      • primarily because of its advanced technology [?]
• the telescope's infrared capabilities
  • allow it
    • to detect light
      • from the universe's earliest epochs.

Understanding the Meaning

Let's start reading from the beginning:

The sentence tells us:

• The James Webb Space Telescope captured images
  • of a specific galaxy cluster (SMACS 0723)
  • in unprecedented detail

revealing thousands of previously unseen celestial...

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

• All choices begin with "objects" - so that word is certain
• What varies is the punctuation:
  • around "primarily because of its advanced technology"
  • and what comes after that phrase

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

The sentence continues: "the telescope's infrared capabilities allow it to detect light from the universe's earliest epochs."

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

• "revealing thousands of previously unseen celestial objects"
  • This is telling us what the telescope discovered
• "primarily because of its advanced technology"
  • This is a quick explanatory phrase
  • It's telling us WHY the telescope could reveal so many objects
  • It's an aside - additional information tucked into the sentence
• "the telescope's infrared capabilities allow it to detect light from the universe's earliest epochs"
  • This is a complete thought - a full sentence
  • It's explaining WHAT that "advanced technology" actually is
  • It's giving us the specific details about the technology

What do we notice about the structure here?

• The phrase "primarily because of its advanced technology" is a parenthetical element
  • It's adding explanatory information
  • It should be set off with commas
• The clause "the telescope's infrared capabilities allow it to detect light..." is a complete sentence that's explaining something
  • It's telling us specifically what the "advanced technology" is
  • It's elaborating on the concept mentioned just before it
  • This is exactly what a colon does - it introduces an explanation or elaboration

So we need:

• A comma after "objects" to start setting off the explanatory phrase
• A colon after "technology" to introduce the specific explanation of what that advanced technology is

The correct answer is Choice D: "objects, primarily because of its advanced technology:"

GRAMMAR CONCEPT APPLIED

Using Colons to Introduce Explanations and Elaborations

When you want to introduce a complete sentence that explains or elaborates on something you just mentioned, use a colon. The part after the colon should provide specific information or details about something in the statement before the colon (called an independent clause in grammar terms).

Pattern:

• Statement mentioning a concept: The team succeeded because of their preparation
• Colon + specific explanation: The team succeeded because of their preparation: they had practiced every scenario for three months

In this question:

• Statement: "revealing thousands of previously unseen celestial objects, primarily because of its advanced technology"
  • This mentions "advanced technology" as the reason
• Colon introduces the explanation: "the telescope's infrared capabilities allow it to detect light from the universe's earliest epochs"
  • This explains specifically WHAT that advanced technology is

Additional principle: Parenthetical or explanatory phrases should be set off with commas:

• Without parenthetical: "The telescope revealed objects because of its technology"
• With parenthetical: "The telescope revealed objects, primarily because of its advanced technology"
  • The comma signals that "primarily" is adding emphasis/clarification