There's not the slightest doubt about that.

Then, you see, there are scarcely any mountains to speak of so far, only ranges of low hills." "And that means, I suppose," said Zaidie, "that they've all been worn down as the mountains of the earth are being.

I was reading Flammarion's 'End of the World' last night, and he, you know, describes the earth at the last as just one big plain of land, no hills or mountains, no seas, and only sluggish rivers draining into marshes.
"I suppose that is what they're coming to down yonder.

Now, I wonder what sort of civilisation we shall find.

Perhaps we shan't find any at all.