Question 82·Easy·Boundaries
The Chicago River, which flows backward because of a 1900 engineering _____ now a popular kayaking route.
Which choice completes the text so that it conforms to the conventions of Standard English?
For boundaries questions, identify whether the inserted phrase is nonessential by temporarily removing it and checking whether the remaining sentence is complete. If it’s nonessential, it must be enclosed with matching punctuation (commas with commas, dashes with dashes). Also remember that semicolons and colons can only appear after a complete independent clause.
Hints
Strip away the middle clause
Temporarily remove the words starting with which. What is the basic sentence that remains?
Decide if the “which” clause is extra information
Ask whether the sentence still makes sense if the which clause is removed. If it does, that clause is nonessential.
Match the punctuation used to open the clause
Look at the punctuation right before which. What punctuation normally comes in pairs to set off nonessential information?
Check semicolon/colon requirements
A semicolon or colon must come after a complete sentence. Do the words before the blank form a complete independent clause?
Step-by-step Explanation
Find the core sentence
Mentally remove the descriptive clause starting with which:
The Chicago River is now a popular kayaking route.
This shows the which clause is extra information inserted into the middle of the sentence.
Use the rule for nonessential (nonrestrictive) clauses
A nonessential clause in the middle of a sentence is typically set off by matching punctuation (commas or dashes).
Because the sentence already has a comma after River, the nonessential clause has been opened with a comma, so it should be closed the same way.
Eliminate choices that don’t fit punctuation rules
- Semicolons and colons must follow a complete independent clause. The text before the blank is not a complete sentence because the main verb (is) comes after the blank.
- A closing dash would not match the opening comma used to introduce the nonessential clause.
Choose the option that correctly closes the clause
The option that closes the nonessential which clause with a matching comma and correctly returns to the main clause is project, is.