Upon a knoll which the drifting sand had not yet buried was a thin, wiry covering of grass. That was all, but the sight brought tears to his eyes. He grounded the machine and stepped out, treading warily lest he destroy even one of the struggling blades.
If these are the only plants left in the world, how is there enough oxygen left to support them, much less a 'human'?
Unless there are enough other plants or some other mechanism to generate oxygen.
