Examkin

Question

Difficulty: EasyClause Boundaries and Linking

Historically, planetary scientists believed that the Venusian atmosphere was completely dry and devoid of water. Recent satellite observations, however, have detected trace amounts of water vapor in the planet's upper _______ this unexpected discovery has prompted researchers to completely reevaluate their models of the chemical processes occurring within the thick clouds of Venus.

Which choice completes the text so that it conforms to the conventions of Standard English?

  1. A
    atmosphere, but this
  2. B
    atmosphere, this
  3. atmosphere; thisAnswer
  4. D
    atmosphere this

Answer

atmosphere; this
The sentence contains two independent clauses: the first ends with 'upper atmosphere' and the second begins with 'this unexpected discovery.' To link two independent clauses without a coordinating conjunction, a semicolon is required. Therefore, the option containing a semicolon is the correct choice.

Step-by-Step Solution

1
Identify the clause boundaries in the sentence.
The text contains two independent clauses: the first is 'Recent satellite observations, however, have detected trace amounts of water vapor in the planet's upper atmosphere' and the second is 'this unexpected discovery has prompted researchers to completely reevaluate their models of the chemical processes occurring within the thick clouds of Venus.'
Determining where one clause ends and the next begins helps identify the correct punctuation or conjunction needed to link them.
2
Evaluate the grammar required to link the clauses.
Since both clauses are independent, they must be linked using a period, a semicolon, or a comma paired with a coordinating conjunction.
Joining two independent clauses with only a comma creates a comma splice, while joining them with no punctuation creates a run-on.
3
Select the option that correctly links the two independent clauses.
The option containing a semicolon followed by 'this' correctly links the clauses without violating grammar or logical flow.
A semicolon is a standard and correct way to link two closely related independent clauses.

Key Concept

Two independent clauses must be separated by a period, a semicolon, or a comma combined with a coordinating conjunction.
Rate this question

Topics

Clause Boundaries and Linking

More questions from this topic