[amp_mcq option1=”on or off” option2=”on and off” option3=”regularly” option4=”No correction required” correct=”option4″]
The correct answer is D. No correction required.
The phrase “off and on” means “intermittently” or “occasionally.” In this sentence, it means that the person has been working on compiling the dictionary for several years, but not continuously. They may have worked on it for a few months, then taken a break, then worked on it again.
The other options are incorrect because they do not accurately reflect the meaning of the sentence. Option A, “on or off,” means “either on or off.” This does not make sense in the context of the sentence, because the person has been working on the dictionary for several years, not just occasionally. Option B, “on and off,” is the same as option A. Option C, “regularly,” means “at regular intervals.” This also does not make sense in the context of the sentence, because the person has not been working on the dictionary at regular intervals.