It's going to be tangent to the level surface, right?

它是与等值面相切的，对不对？

youdao

We have seen that the gradient is perpendicular to the level surface.

我们已经知道，梯度是垂直于等值面的。

youdao

Then you know that the gradient of g is perpendicular to the level surface.

那么就知道了g的梯度,是垂直等值面的。

youdao

The land surface pokes just a couple of meters on average above sea level, making it the lowest-lying nation in the world.

VOA: standard.2009.10.17

So, one difference between photoelectron spectroscopy and, for example, the photoelectric effect is that in this case, we're not just looking at one energy level, which is what we were looking at from the surface of a metal, now we're talking about this gaseous atom.

光电子能谱与光电效应的不同点在于，以这种情况为例，我们不只关心一个能级，就像原来在金属表面那样，现在我们研究的是气体原子，所以，我们可以从原子中。

麻省理工公开课 - 化学原理课程节选

But no matter what happens, the game set everyone off on the same footing, on the same level surface.

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Users simply need to place their handsets in the center of the space, on a level surface, such as a table or chair.

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In preparation for the meeting, construction workers built an elevated floor to make a level surface and covered the windows so no one could get a glimpse of the meeting.

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