If one could don magic spectacles – with lenses that make the murky depths of the ocean become transparent – and look back several centuries to an age before widespread abuse of the oceans began, even the most (i)____________ observer would quickly discover that fish were formerly much more abundant. Likewise, many now-depleted species of marine mammals would appear (ii)____________. But without such special glasses, the differences between past and present oceans are indeed hard to (iii)____________. A. casual B. threatened C. ignore D. prescient E. plentiful F. discern G. clearheaded H. unfamiliar I. dismiss