In 1956, experimental physicist Chien-Shiung Wu performed a landmark experiment to test the law of conservation of parity, which states that physical systems and their mirror images behave identically. Wu ______ cooled radioactive cobalt-60 atoms to near absolute zero, allowing her to observe that beta particles were emitted asymmetrically. This groundbreaking result disproved a widely accepted theory, fundamentally altering the course of modern particle physics.
Which choice completes the text so that it conforms to the conventions of Standard English?
- A, working in collaboration with the National Bureau of Standards—
- —working in collaboration with the National Bureau of Standards—Cevap
- C—working in collaboration with the National Bureau of Standards,
- D, working in collaboration with the National Bureau of Standards
Cevap
The option that uses matching em dashes to set off the nonessential phrase 'working in collaboration with the National Bureau of Standards'.
The phrase 'working in collaboration with the National Bureau of Standards' is a nonessential parenthetical modifier that provides additional context about the physicist Chien-Shiung Wu but is not grammatically necessary for the main clause. Nonessential elements must be set off from the rest of the sentence using a pair of matching punctuation marks, such as two commas, two parentheses, or two em dashes. The correct option uses matching em dashes to set off this parenthetical information, which maintains grammatical consistency and clarity.
Adım Adım Çözüm
Anahtar Kavram
Punctuation of Nonessential Elements