GRE Text Completion: JiJing 1373-GRE填空机经1373题 - FW74VB53184H064EA

Although trains may use energy more (i)____________ than do automobiles, the latter move only when they contain at least one occupant, whereas railway carriages spend a considerable amount of time running up and down the tracks (ii)____________, or nearly so. A. lavishly B. vacant C. efficiently D. unimpeded E. routinely F. overloaded