Question 15·Hard·Boundaries
Marine fossils have been discovered at elevations exceeding 26,000 feet in the _____ fossilized shells, coral fragments, and microfossils — clear evidence that these towering peaks were once submerged beneath an ancient ocean.
Which choice completes the text so that it conforms to the conventions of Standard English?
For boundaries/punctuation questions, first determine whether the words before the blank form an independent clause. Then identify what follows (another independent clause vs. a list/explanation). Use a colon to introduce a list after a complete clause; use a semicolon only between two complete clauses; avoid using a comma to introduce a list after a full clause.
Hints
Test for a complete sentence
Cover the words after the blank and see whether the sentence up to the blank can stand alone as a complete sentence.
Identify what follows the blank
Decide whether the words after the blank form an independent clause or a list of examples.
Match punctuation to function
Use a colon to introduce a list after a complete clause; use a semicolon only to connect two independent clauses.
Step-by-step Explanation
Check whether the first part is a complete clause
Read the sentence up to the blank:
Marine fossils have been discovered at elevations exceeding 26,000 feet in the Himalayas
This is a complete independent clause (it can stand as a full sentence).
Decide what the next words are doing
The words after the blank ("fossilized shells, coral fragments, and microfossils") form a list that specifies what kinds of marine fossils were discovered.
A colon is used to introduce a list or explanation that follows a complete clause.
Select the punctuation that correctly introduces the list
Because a complete clause comes before the punctuation and a list follows, the correct choice is:
Himalayas: fossilized shells, coral fragments, and microfossils