According to Gerard Kuiper, of the University of Chicago, the escape of gases from the moon's magma may have given the satellite a light, porous consistency, like that of a pumice stone.

芝加哥大学的Gerard Kuiper则提出，可能是月亮上岩浆气体的逃逸赋予了这颗星球轻飘多孔的硬度，就好象浮石那样。

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Of all the mass media, from ancient official or personal inscriptions on stone to today's satellite broadcasts, those printed on paper have had the most profound influence.

ECONOMIST: Millennium issue: COMMUNICATION

The new service replaces a temporary satellite unit which was used as a stepping stone towards a permanent renal ward at the town's hospital.

BBC: Kidney dialysis