As geologists, we examine layers of sediment on the Earth' s surface to approximate the dates of past geologic time periods.

作为地质学家，我们研究地球表面的沉积层以估算过去地质时期的年代。

youdao

That means you need your vector field to be continuous and differentiable everywhere on the surface s.

也就是，向量场是连续的，且在曲面s上处处可微。

youdao

So, s is actually this whole closed surface here.

那么，S实际上是这个完整的封闭曲面。

youdao

The atmosphere is about twenty-percent oxygen and eighty percent nitrogen from Earth's surface to where space begins at one-hundred-twenty kilometers up.

VOA: special.2011.04.06

There are - that's one class of proteins on the surface I'm sorry.

对不起,这是细胞膜蛋白的一个种类

耶鲁公开课 - 生物医学工程探索课程节选

Then,seventy-million years ago, the Earth's surface, or crust,pushed upward.

VOA: special.2010.01.04

Solar energy can, of course, be gathered on Earth, but only about half of the sun's radiation ever makes it to the Earth's surface--the rest is either absorbed by the atmosphere or reflected back by clouds.

FORBES: Galactic Gold Mine?

It will make its closest approach to the Sun - at a distance of not much more than a million km from the Sun's surface - on 28 November.

BBC: Comet Ison caught on film by Deep Impact craft

It comes from a garden wholesaler, which provides the high quality soil, taken deep beneath the earth's surface -- 10 meters down, in fact.

CNN: Tokyo restaurant dishes up the dirt