Examkin

Question

Difficulty: EasyCommas with Nonessential and Parenthetical Elements

In 1943, Jacques Cousteau and Émile Gagnan co-invented a new breathing apparatus for underwater exploration. The Aqua-Lung , which allowed divers to breathe underwater, revolutionized marine research. Scientists could finally observe aquatic life for hours at a time.

Which choice best punctuates the underlined portion of the sentence?

  1. NO CHANGEAnswer
  2. B
    , which allowed divers to breathe underwater
  3. C
    ; which allowed divers to breathe underwater,
  4. D
    , that allowed divers to breathe underwater,

Answer

NO CHANGE
The relative clause starting with 'which' is nonessential because 'the Aqua-Lung' is a specific, named device. As a nonessential element in the middle of a sentence, it must be enclosed by a pair of commas. The original text correctly places a comma before 'which' and after 'underwater.'

Step-by-Step Solution

1
Determine if the underlined clause is essential or nonessential.
The clause 'which allowed divers to breathe underwater' provides extra information about 'the Aqua-Lung' but is not needed to identify what the device is. It is nonessential.
Nonessential information must be set off from the rest of the sentence with punctuation, while essential information should not be set off.
2
Choose the correct punctuation to set off the nonessential clause.
Since the clause appears in the middle of the sentence, it requires a pair of commas—one before and one after the clause.
Setting off a middle-of-the-sentence parenthetical element requires punctuation on both sides to prevent grammatical errors.
3
Evaluate the choices for comma placement and pronoun usage.
The option containing the original phrasing correctly uses a pair of commas. The option missing the second comma is incomplete. The option using 'that' with commas incorrectly punctuates a restrictive pronoun. The option using a semicolon creates a fragment.
Only the original punctuation maintains correct sentence structure.

Key Concept

Commas with Nonessential and Parenthetical Elements
Rate this question

Topics

Commas with Nonessential and Parenthetical Elements

More questions from this topic