Because acidic water makes it harder to produce those shells.

因为海水的酸性很难产生这些壳体。

The shelled bodies of turtles, for example, evolved between 250m and 200m years ago, while the body plans of scorpions have been around for more than 400m years.

例如，海龟的壳体是在2.5～2.0亿年前进化的，而蝎子的体型方案已超过4亿年的历史。

Amidst this expanse of nothingness floated a huge egg-shaped shell.

在这片无尽的虚无中，漂浮着一个大的蛋形壳体。

And that model consists of shells and now subshells.

该模型由壳体和现在的子壳体组成。

This aircraft will be powered by two rear-mounted 500 kilowatt electric turbo fans which turn a fan inside a shroud and so look a bit like jet engines.

这架飞机将由两台后置的500千瓦电动涡轮风动力，这些风在壳体内旋转，因此看起来有点像喷气发动机。

As the red giant heats up and its outer  shell expands, it is continually stripped of hydrogen by the immense gravitational pull  of its neighbouring white dwarf.

随着红星温度升高， 其外层壳体膨胀，在邻近白矮星大引力作用下， 不断剥离氢元素。

This hollow shell will be of such gigantic proportions that it could one day fully enclose the Sun and capture all of its solar energy output.

这个空心壳体规模如此大，将来有一天可以完全包裹太阳并捕获其全部太阳能输出。

In 1955, American scientists Heinz Frankel-Konrad and Robley-Williams found that viruses can be single strands of the genetic material RNA wrapped in a shell, capsid.

1955年，美国科学家海因茨·弗兰克尔-康拉德和罗布利·威廉姆斯发现，病毒可以是包裹在壳体（即衣壳）内的单链遗传物质RNA。

One is through the ratio in shells between two isotopes of oxygen This ratio varies with ambient temperature in a predictable manner.

一种是通过壳体中两种氧同位素的比例来判断，这个比例会以可预测的方式随环境温度变化。

The core is made of clay soils that are highly  impermeable to seepage, while the outer shells have less stringent specifications.

核心部分由高渗透阻性的黏土构成，而外层壳体的规格要求则较低。

If the yang spirit is returned to the shell, spirit and body will merge and you will be able to live as long as the sky and the earth.

如果阳神回归壳体，精神与身体将合二为一， 你将能够活得和天地一样长久。

We've been working together with the folks of Ionic around Ionic and Next integrations, and they have really cool ways of embedding your apps in native shells.

我们一直与Ionic团队合作，围绕Ionic和Next进行集成，他们了非常酷的方法，能将你的应用嵌入到原生壳体中。

That transaxle, I guess it combines the differential, the transmission, and the axle all into one compartment.

那变速箱，我想它是将差速器、变速器和半轴全部整合到一个壳体内的。

Basically, it's like having a bunch of laser pointers inside the shell shooting all around the room.

基本上，这就像是在壳体内有一大堆激光笔，向房间的各个方向发射。

The casing is another word for the case or the cover or outside of a machine.

外壳是指机器的壳体、盖子或外部。

And so, the Dyson Sphere is essentially trying to construct some giant shell around a star.

因此，戴森球基本上是试图在恒星周围建造一个大的壳体。

Then the shell contacts the lever arm at each pipe like this, which causes them to roll forward, down the ramp, hopefully into the dominoes.

于是， 壳体就这样接触到每根管子上的杠杆臂，使得它们向前滚动， 顺着斜坡下滑，希望最终能撞倒多米诺骨牌。

At this point you can choose to live forever in the earthly realm or leave the mundane shell and return to the ten continents.

此时你可以选择永远生活在尘世， 或离开凡俗的壳体， 返回十洲。