我们将零点定义为每种元素，在室温和正常大气压下，在其自然状态下的焓。

What we define as zero is the enthalpy of every element in its natural state at room temperature and ambient pressure.

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在正常大气压下，二氧化碳是无色无味气体，密度比空气大，是空气的1.5倍。

Under normal atmospheric conditions, carbon dioxide exists as a colorless, odorless gas which is about 1.5 times heavier than air.

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杨利伟进一步解释说：“我们的很多物品在上天前都是有大气压封到里面，随着在太空中飞行，可能会泄压也会有一些声音发出，这样的话需要我们去辨认，我想这些都是很正常的事情。”

He said air leaking out of the objects in the capsule could also cause noise. "I think it is normal," Yang said. "it is necessary to carefully identify the cause."

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杨利伟进一步解释说：“我们的很多物品在上天前都是有大气压封到里面，随着在太空中飞行，可能会泄压也会有一些声音发出，这样的话需要我们去辨认，我想这些都是很正常的事情。”

He said air leaking out of the objects in the capsule could also cause noise. "I think it is normal," Yang said. "it is necessary to carefully identify the cause."

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