Archaeologists have estimated that the pre-Columbian Native American city of Cahokia, located across the Mississippi River from modern-day St. Louis, Missouri, had as many as 20,000 inhabitants in the year 1150 blank it one of the largest cities in North America at the time.
Which choice completes the text so that it conforms to the conventions of Standard English?
CE making
CE. Making
CE, making
CE; making
Choice C is the best answer. The phrase “making…at the time” provides additional information about Cahokia that’s not required for the sentence to make sense or function grammatically. As a nonessential supplement, this phrase should be separated from the rest of the sentence with a comma.
Choice A is incorrect. This choice results in a run-on sentence. The nonessential descriptive aside “making…at the time” needs to be separated from the rest of the sentence with a comma. Choice B is incorrect. This choice results in a sentence fragment. “Making…at the time” doesn’t have a subject and can’t stand on its own as a sentence. Thus, it can’t be separated from the rest of the sentence with a period. Choice D is incorrect. This choice results in a punctuation error. “Making…at the time” doesn’t have a subject and can’t stand on its own as an independent clause. Since a semicolon can only link two independent clauses, using one here creates an error.