从而法向量的方向是竖直向上或向下的。

The normal vector is just sticking straight up or straight down.

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甚至可以向上或向下跳几个目录层级，如清单10所示。

You can even jump up a couple of levels, and then down a couple, as shown in Listing 10.

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您可以继续向上或向下钻取以便更好地理解您的业务数据。

You can continue drilling up and down to better understand your business data.

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This is important because this molecule here, deoxyribose, is not the same upside down as it is - it's not symmetrical upside down and right side up, it's different because the 5' carbon's either pointed up or pointed down.

这很重要,因为对脱氧核糖来说,不都是像这样自上而下的,不是对称的自上向下或全部向上的,长链不同是由于,5'碳向上或者向下的指向不同

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