GRE Text Completion: JiJing 1373-GRE填空机经1373题 - L6JU7FK1YC9ZZ9T7A

At least one otter species, the sea otter, has a large, often dominating, effect on the structure of its own habitat. There is no evidence that other species have ever exercised such (i)____________ effects. That lack of evidence could merely be because the other species have been studied less thoroughly. However, the size and density of the historic sea otter populations in many Pacific coastal regions (ii)____________ those of other otter species elsewhere, so perhaps the sea otter is indeed (iii)____________ in its effects on habitat. A. ephemeral B. vastly exceed C. unique D. unpredictable E. have little effect on F. destructive G. significant H. roughly parallel I. transitory