GRE Text Completion: JiJing 1373-GRE填空机经1373题 - 77I126705SF4A3NIA

Though it may seem as if more than a century of ____________ has made the electrical grid an all-encompassing web connecting the whole of the continent, many vast and beautiful areas remain without power. A. refinement B. expansion C. ubiquity D. augmentation E. omnipresence F. isolation