A high concentration of ash ingested by a jet engine can become molten and cause engine failure, which is why planes are not allowed to fly through the cloud.

高浓度的火山灰一旦被吸入喷气发动机就会融化，并且造成引擎故障，因此喷气式飞机是不允许在火山灰云层中穿行的。

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The fresher water, though, is put through the same process twice more and eventually has its salt concentration reduced to 1%.

但是淡水还要经过两次以上这样的工艺处理过程，最终将盐浓度降低到1%。

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This occurs when the comet dives close to the sun and Earth passes through the resulting thick concentration of cosmic debris.

彗星在靠近太阳的地方俯冲留下了浓厚的宇宙尘埃，地球穿过这些尘埃产生了“流星风暴”。

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The only way he could have obtained a degree with that on it is through pursuing an independent concentration.

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United had let a two-goal lead slip against Liverpool at home in a season which has been marked by them conceding leads through lapses in intensity and concentration.

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It is the process of moving water from an area with a low concentration of dissolved material, such as salt, to a place with a high concentration, by passing through a membrane.

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