The principal floor is for everyday functions.

地板的主要是日常职能。

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In the principal room, a grey carpet was removed to reveal the original pine floor.

在主房间里，一块灰色的地毯被挪开了，使原有的松木地板露了出来。

《柯林斯英汉双解大词典》

Because the majority of the bedrooms are on the lower levels, the architects aligned the second floor so that the principal Spaces take in the best views.

因为主卧室在低层，建筑师为了均衡二层，因此主要的空间设置在最好的视野处。

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Methane is the principal component of natural gas, and massive amounts of it are trapped in reservoirs beneath the sea floor and under a layer of the ice-like substance.

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