A so-called "planetary nebula" is a confusing misnomer because these clouds have nothing to do with planets. As a medium-size star nears the end, it puffs out into a red giant — about 100 to 1,000 times its original size — eventually engulfing the space around it, including any nearby worlds.
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由于表面粗糙、精度不足等问题，金属件打印完成后须经历一系列复杂后处理流程，其中成本主要集中在打磨、抛光等表面精加工流程。更值得关注的是，目前大量后处理环节仍依赖人工操作。这不仅意味着高昂的人力成本，还存在重复性劳动导致的人员疲劳、效率波动以及质量一致性难以保证等问题。
As the economy grows increasingly reliant on spending by the very wealthy, it has also become more vulnerable to a sudden downward correction in share prices.
Маргарита Щигарева