Question

a british scientist peter whibberley has observed, the earth is not a very good time - keeper. earths 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 ____ time based on the planets 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? choice 1 answer: a added, whenever b adder whenever c added whenever d added whenever

Explanation:

In Standard English, a comma is used to separate an introductory adverbial clause or phrase from the main clause. "Whenever" is an adverbial conjunction, and a comma should follow the main - clause verb "added" when starting a subordinate clause with "whenever".

Answer:

A. added, whenever