himba

OG233的解释中Both D and E fail to use and to introduce the last item in the list, which is sleeping in these constructions. In E, while raising has no logical referent, producing only the absurd statement that fatigue has raised efficiency. 说明ETS已经把E中and fatigue后面的成分单独看成一个句子，于是while的指代就十分明确: fatigue，而逻辑上应该指代“shift-work equations”。