地球历史上的这次重大灾难以物种的大量消亡为标志；当时，地球上多达一半的物种都灭绝了。
This break in Earth's history is marked by a mass extinction, when as many as half the species on the planet became extinct.
作为银河系最密集的一部分，大量恒星周期性诞生消亡产生了这些尘埃。
Being such a crowded part of the Galaxy, there have been many cycles of starbirth to produce such dust.
这也意味着大的恒星快速地释放大量的物质，在大规模的爆炸中燃烧自己，从而寿命短，消亡早。
That also means that massive stars live fast and die young, quickly shedding huge amounts of material and burning themselves out in what are thought to be spectacular explosions.
许多传统技艺濒临消亡，大量具有历史、文化价值的珍贵实物与资料遭到毁弃。
Many traditional techniques are endangered, a large number of precious information and material with historical and cultural values was destroyed.
许多传统技艺濒临消亡，大量具有历史、文化价值的珍贵实物与资料遭到毁弃。
Many traditional techniques are endangered, a large number of precious information and material with historical and cultural values was destroyed.
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