1·In this so-called "fire tetrahedron", heat breaks the chemical bonds of the fuel's hydrocarbon chains.
在这个所谓的“燃烧四面体”中，热量打破了燃料的烃链上的化学键。
2·The shape of a water molecule is such that each H2O molecule is surrounded by four neighbours arranged in the shape of a triangular pyramid - better known as a tetrahedron.
一个水分子的形状是这样的：相邻地四个水分子组成一个金字塔形的四面体。
3·A tetrahedron with four equilateral triangular faces.
有四个等边三角形面的四面体。
4·Experiment results show that using this new algorithm for tetrahedron, finite element model can provide well visual result.
实验表明，研究的新算法用于四面体单元的有限元模型，具有良好的切割处理效果。
5·Thus one has a triangle in, a tetrahedron in, etc.
因此在空间中是一个三角形，空间中是一个四面体，等等。