If the glass were kept hot enough, it would flow over the molten tin until the top surface was also flat, horizontal and perfectly parallel to the bottom surface.

如果玻璃保持足够的温度，它就会在熔化的锡中流动，直到顶部表面也变得平整、水平，与底部表面完全平行。

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A package with pins distributed over much or all of the bottom surface of the package.

一种封装，插脚分布在封装底部的大部分或全部表面。

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The concrete foundation bottom surface should be smooth solid, not into the pot bottom.

混凝土基础底面要平整夯实，基础底部不能作成锅底状。

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If they hit the bottom surface before passing through, they are reflected off and absorbed at the top - and thus are not detected at the other end of the plates.

BBC: Neutrons could test Newton's gravity and string theory

On the bottom side, the notebook is sealed in such a way that you can't easily get at the battery, SSD or RAM. (This is pretty typical for Ultrabooks.) That bottom surface is also where you'll find the speaker strip, which is somewhat unusual: laptop speakers are usually located in the keyboard area or around the sides.

ENGADGET: Acer Aspire S7 review (13-inch): great Ultrabook, a shame about the battery life

Because cold water releases more CO2 into the air than warm water, the rate at which bottom water rises to the surface has a profound effect on the atmosphere above.

CNN: Scientists discover new species in ocean's depths