假如现在这个比率是最低的、并且放在防喷器上方的关键性管道适应了高帽之前、仍然保持低比率，那时候泄漏的油约相当于现在已经漏掉量的一半。

If the rate is at the low end of the range and was lower still before a key pipe on top of the blowout preventer was cut to accommodate the top hat, about half as much oil has been spilled so far.

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在油井发生爆炸以及油井起火后，海底上的防喷器本来应该自动将油井封住，但是未能做到这一点，导致大规模的石油泄漏。

Following the explosion and fire on the rig, the blow-out preventer on the sea bed should have automatically sealed the well, but it failed, resulting in the massive oil spill.

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但在福岛则不同，释放气体是必须的以避免防泄漏系统内部压力过高。

At Fukushima it has been necessary to release gases because the containment pressure became too high.

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