This gas is hydrogen sulfide, rises up and mixes with oxygen in the underground water that sits in the cracks and fissures in the limestone.

这种气体是硫化氢，上升后与石灰岩裂缝中地下水的氧气混合。

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Instead, spent fuel rods in the U.S. are currently stored in underground pools of water or in dry-cask storage, where older fuel is put into steel cans filled with inert gas and then stored in silos.

相反，目前美国把用过的燃料棒存放在地下的水池里或装在干桶里，其中年代较远的燃料被放入充满惰性气体的钢罐里，然后存放在废弃的洲际导弹发射井中。

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Found underground and on the sea floor, methane hydrate consists of natural gas molecules trapped within a lattice of frozen water molecules.

甲烷水合物主要存在于地下以及海底，由甲烷分子被锁在固态水晶体格中所组成。

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Many federal and state regulators say hydraulic fracturing, which injects a mix of water and chemicals thousands of feet underground to crack open shale and release natural gas, is safe when done properly and thousands of sites have few complaints of pollution.

NPR: AP: NY Fracking Held As Cuomo, RFK Jr. Talk Health

Cuomo said late Monday that he hasn't given a deadline for the state health and environmental conservation commissioners he appointed to advise him on a decision on whether to drill for gas using hydraulic fracturing, or fracking, which injects a mix of water and chemicals thousands of feet underground to crack open shale and release natural gas.

WSJ: NY senators seek fracking delay to await key study

Fracking involves drilling horizontally into the rock, forcing sand and water underground to cause tiny fractures that release gas from the shale.

BBC: NI shale gas deposits 'could be worth ?80bn' says report