This is a natural opening for a narrative.

这是叙述文常用的一种开头方式。

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In the literal opening, he gives what looks like a kind of natural history of the polis.

在本书开始的地方，他给了一种类似,城邦自然演变历史的说法。

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This hole is either a heart defect (atrial septal defect) or an enlarged natural opening (foramen ovale) that is supposed to close soon after birth.

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The mansions were often located on a natural cave opening incorporated in the foundation.

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Our natural resources and opening to the Gulf makes up a potential superpower, if we can overcome years of petty provincialism and find the political will to see the region in its entirety.

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