GRE Text Completion: JiJing 1373-GRE填空机经1373题 - QK5EXFJASK5F37M8A

Among wide-ranging animal species, populations at the edge of the species' range are frequently exposed to less (i)____________ and more variable conditions than those in other parts on the range. As a results, the animals' abundance is often (ii)____________. A. erratic B. lower at the periphery C. favorable D. unaffected by habitat E. demanding F. underestimated by researchers