sat suite question viewer
As British scientist Peter Whibberley has observed, “the Earth is not a very good timekeeper.” Earth’s slightly irregular rotation rate means that measurements of time must be periodically adjusted. Specifically, an extra “leap second” (the 86,401st second of the day) is blank time based on the planet’s rotation lags a full nine-tenths of a second behind time kept by precise atomic clocks.
Which choice completes the text so that it conforms to the conventions of Standard English?
Explanation
Choice D is the best answer. The convention being tested is punctuation between a verb and a preposition. When, as in this case, a verb (“is added”) is immediately followed by a preposition (“whenever”), no punctuation is needed.
Choice A is incorrect because no punctuation is needed between the verb and the preposition. Choice B is incorrect because no punctuation is needed between the verb and the preposition. Choice C is incorrect because no punctuation is needed between the verb and the preposition.