From the beginning, the cloud hanging over the whole hydrogen enterprise has not been the power source as such, but the intractable difficulty of distributing and storing the stuff.

从一开始，盘旋在氢能源开发企业头上的阴云已经不是像这样的动力来源的问题，而是那些棘手的配送和储存原料的难题。

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The presence of hydrogen in the soil, meanwhile, could provide a source of fuel for lunar visitors.

在土壤中存在的氢，将为月球的探访者带来燃料。

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It suggests to Farihi that both the hydrogen and the heavy elements come from the same source - planetary debris - which would be most likely to hold hydrogen in the form of water.

这一事实向Farihi表明氢和重元素来自同一来源——行星残骸——其很有可能以水的形式保存氢。

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And yet what is worrying is that the big firms are largely ignoring natural gas as a source of hydrogen.

ECONOMIST: How green is your hydrogen?

So far, nobody has come up with an answer to this difficulty that does not involve shifting to another, presumably more expensive, source of hydrogen.

ECONOMIST: Fuel cells hit the road

The next is that run through a fuel cell, hydrogen is an efficient source of energy.

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