 Which of these was not a consequence of the Great Atomic Wars?
The planet itself was tough enough—barren, desolate, forbidding; enough to stop the most adventurous and dedicated. Nothing but what had stopped us could stop a sandcat: sand in the delicate mechanism of the atomic engine. But no; she blamed it all on me somehow: So we were out walking on the spongy sand of the Martian desert. "Maybe there isn't any uranium in this sector at all. She had been just as much inflamed by the idea of coming to Mars to help in the search for uranium as I was. We knew the pay was poor, but we had felt it a sort of obligation, something we could do as individuals to keep the industries of radioactives-starved Earth going. No, we had decided together to come to Mars—the way we decided together on everything. Maybe we shouldn't have come to Mars after all. I watched her, sleeping peacefully, a wayward lock of her soft blonde hair trailing down over one eyebrow, and it seemed hard to believe that we'd exchanged Earth and all it held for us for the raw, untamed struggle that was Mars. Earth needed radioactives, and the only way to get them was to get out and look. The great atomic wars of the late 20th Century had used up much of the supply, but the amount used to blow up half the great cities of the world hardly compared with the amount we needed to put them back together again. The wreckage of New York and Shanghai and London and all the other ruined cities had been hidden by a shining new world of gleaming towers and flying roadways. They had used their atomics to make bombs. It was an atomic world. Everything: power drills, printing presses, typewriters, can openers, ocean liners, powered by the inexhaustible energy of the dividing atom. But though the energy is inexhaustible, the supply of nuclei isn't. After three centuries of heavy consumption, the supply failed. And that started the chain of events that led Val and me to end up as a madman's prisoners, on Mars. With every source of uranium mined dry on Earth, we had tried other possibilities. Project Sea-Dredge was trying to get uranium from the oceans. But there wasn't forty or fifty years' worth of raw stuff to tide us over until then. Millions of starving, freezing humans tooth-and-clawing in it in the useless shell of a great atomic civilization. So, Mars. It's a stopgap effort, just to keep things moving until Project Sea-Dredge starts functioning.
 Multiple planets were settled by various countries in a display of power
 Limited resources ran out over time  Multiple planets were settled by various countries in a display of power  All major types of power sources changed  Earth decided to run supply missions to Mars