Bones are hard, mineralized structures that rot away slowly.

骨头是坚硬的矿化结构，会慢慢腐烂。

In fact, just like coral reefs, they will bunch together and create these hard structures that you can actually walk on.

事实上，就像珊瑚礁一样，它们会聚集在一起，形成一种坚硬的结构，让人可以在上面行走。

But with the new adhesive you could assemble this mix of hard and soft structures much more quickly.

但是使用新的粘合剂，您可以更快地组装这种硬质和软质结构的混合物。

Sponges have hard structures within their bodies called spicules, crystalline forms made from amorphous silica that grow and branch to form wicked shapes.

海绵体内有称为针状体的坚硬结构，由无定形二氧化硅制成的结晶形式可以生长和分枝形成邪恶的形状。

Diamonds are hard because of their molecular structure, each carbon atom forms four covalent bonds with the atoms around it, which forms an exceptionally hard crystal structure.

金刚石坚硬是因为其分子结构，每个碳原子与相邻的原子形成四个共价键，从而形成极其坚硬的晶体结构。