Examkin

Question

Difficulty: HardCommas with Nonessential and Parenthetical Elements

Deep within the Guatemalan rainforest, archeologists have discovered a vast network of Mayan ruins previously hidden by dense canopy. LiDAR; a laser mapping technology, has revealed structures that were previously invisible under the forest floor. This groundbreaking data has revolutionized our understanding of pre-Columbian civilization.

Which choice best punctuates the underlined portion of the sentence?

  1. A
    NO CHANGE
  2. LiDAR, a laser mapping technology, has revealed structures that were previously invisibleAnswer
  3. C
    LiDAR, a laser mapping technology has revealed structures that were previously invisible
  4. D
    LiDAR, a laser mapping technology, has revealed structures, that were previously invisible,

Answer

LiDAR, a laser mapping technology, has revealed structures that were previously invisible
The correct answer properly encloses the nonessential appositive phrase 'a laser mapping technology' within a pair of commas. Because this phrase is parenthetical, removing it leaves a grammatically complete main clause. Additionally, it correctly avoids placing commas around the restrictive relative clause 'that were previously invisible', keeping the modifier linked to the noun it restricts.

Step-by-Step Solution

1
Identify any parenthetical or nonessential elements in the sentence.
The phrase 'a laser mapping technology' describes LiDAR but is not essential to the core meaning of the sentence.
Identifying nonessential modifiers allows you to apply the appropriate comma rules to set them off from the main clause.
2
Determine the punctuation required for the nonessential appositive.
A pair of commas must enclose 'a laser mapping technology' (one after 'LiDAR' and one after 'technology').
Using a semicolon is incorrect because a semicolon must separate two independent clauses, and omitting one of the commas leaves a single dangling comma.
3
Analyze whether the relative clause starting with 'that' requires commas.
The clause 'that were previously invisible' restricts the meaning of 'structures' and is essential to the sentence, so it must not have commas.
Restrictive clauses are necessary to specify the referent and should never be isolated with commas.

Key Concept

Commas with Nonessential and Parenthetical Elements
Rate this question

Topics

Commas with Nonessential and Parenthetical Elements

More questions from this topic