Eunice Newton Foote was an American scientist who conducted early experiments on climate science. In the passage below, a punctuation mark is missing to properly set off a nonessential relative clause. Which punctuation mark must be placed in the blank to ensure the sentence conforms to the rules of Standard English conventions?
Answer:In 1856, American scientist Eunice Newton Foote conducted pioneering laboratory experiments to analyze the heat-trapping properties of various atmospheric gases. Her brief paper—which described how carbon dioxide and water vapor could warm the Earth's atmosphere【—】was read aloud by a male colleague at an annual scientific conference because women were not permitted to present their own research. This groundbreaking presentation marked the earliest recorded scientific link between carbon dioxide and global climate change.
Answer
an em dash (—)
The correct punctuation mark to place in the blank is an em dash (—). In Standard English conventions, nonessential elements (such as appositives, parenthetical phrases, or relative clauses) must be set off from the rest of the sentence with matching pairs of punctuation. Because the relative clause 'which described how carbon dioxide and water vapor could warm the Earth's atmosphere' is introduced with an em dash, it must also end with an em dash.
Step-by-Step Solution
Key Concept
Punctuation of Nonessential Elements