And they come in their own very hard shell.

它们都有非常坚硬的外壳。

For one, they have a hard, mineralized layer on the outside.

首先，鳞片表面有非常坚硬的矿化层。

This cooling liquid formed a very hard rock known as granite.

这种冷却液体形成了一种非常坚硬的岩石，被称为花岗岩。

It's not even wooden; that's rock-solid.

门甚至不是木头做的；是非常坚硬的实心材质。

The nails on our fingers and toes are only parts of the skin which have grown very hard.

我们的手指与脚趾上的指甲, 只是长得非常坚硬的一部而已。

This material forms very hard ceramics that also find use in everything from car brakes to bulletproof vests.

该材料可制造非常坚硬的陶瓷，而这种陶瓷适用于从汽车制动到防弹背心等很多领域。

Well, the stone is a kind of very hard rock called granodiorite. It is dark grey and pink in color.

石碑由非常坚硬的花岗闪长岩制成。石碑的颜色为深灰色和粉色。

Have you ever seen a diamond? It is a very bright, hard kind of stone, and very dear.

小朋友，你见过钻石吗？钻石，也叫金刚石，是一种非常光亮，非常坚硬的石头，价钱还特别贵。

She thinks it is a very hard cupboard!

她认为这是一个非常坚硬的橱柜！

Brazil nuts have very hard shells.

巴西坚果有非常坚硬的外壳。

It's almost like you have a very hard piece of rock on your skin.

这几乎就像你的上有一块非常坚硬的岩石。

It can be a soft material or it can be a very hard material.

它可以是柔软的材料，也可以是非常坚硬的材料。

It tastes like something really hard and it's been out for like 10 years.

- 它尝起来像非常坚硬的东西，已经出来了 10 。

A few carnivorous eat very hard food, and have specialized adaptations for cracking bones or shells.

一些食肉动物吃非常坚硬的食物，并且有专门的适应能力来破解骨头或贝壳。

And I spent a month or so experimenting with PLA, which is a hard and scratchy, breakable material.

我花了一个的时间用原生树脂做实验。这种材料非常的坚硬、粗糙、易折。

So these things are really tough, and the buildings they're in are probably hardened both inside and out.

所以这些东西非常坚硬，它们所在的建筑内外可能都加固了。

This is like a really hard plaque that discolors your teeth, and at this point, only a dentist would be able to get rid of it.

这就像是一种非常坚硬的牙菌斑，会让你的牙齿变色，这时，只有牙医才能将其清除掉。

" Coal" (coal) is a very hard, black substance that you dig out of the ground to use as fuel, to use for energy.

“煤” （煤炭）是一种非常坚硬的黑色物质，你从地下挖出来用作燃料， 用作能源。

There was a " pearl necklace." " Pearls" are not stones, but they are a very hard substance that you find in an oyster.

有一条“珍珠项链” 。 “珍珠”不是石头，而是一种非常坚硬的物质， 可以在牡蛎中找到。

Cobalt is a hard, shiny metal that is often mixed with other metals. It is very rare but extremely important to the production of batteries.

钴是一种非常坚硬、光亮的金属，经常与其他金属混合存在。这种金属非常罕见，但对电池的生产极为重要。