<p>the agency reports that by rigorously enforcing state regulations , (industrial pollution has been successfully reduced to successful levels) </p>
<p>now i chose : ,(acceptable levels of industrial pollution have been successfully reduced) but the correct answer is : ,(it has succeeded in reducing industrial pollution to acceptable levels) </p>
<p>and i have another question, umm regarding the tense used ''have been '' does it denote something the agency does that still remain in effect ? thanks all.</p>
<p>Unless the the word after the comma is “agency” or “it,” you have a dangling participle, in that it is unclear what “by rigorously enforcing state regulations” is referring to. Since only the post-comma part of the sentence can be changed in the question, the correct answer has to be “it has succeeded…” If you could change the lead-in phrase the sentence could be: “The agency reports that, by its having rigorously enforced state regulations, industrial pollution has been successfully reduced to acceptable levels.” If “have been” were the correct words to use, they would imply that the agency had reduced pollution to a safe level and it remains there.</p>
<p>When stuck, try to not over think the grammar rules too much, but instead rely on what makes sense to you. </p>
<p>For example, look at what the answer you chose is actually saying: The answer you chose states that the levels were ALREADY “acceptable” and have been “successfully reduced” (because vigorous enforcement of state regulations). </p>
<p>If you take a second to think about the statement you would likely realize that they aren’t trying to convey that the agency was already in compliance, but rather that they were not in compliance but brought themselves into such by rigorously enforcing state regulations. Don’t know what your other choices were, but this thought process alone probably would have had you guessing the correct answer.</p>