The packing of spherical atoms of ions is one of the most fundamental structural patterns of nature. 球形原子或离子的堆积是自然界中一种最基本的结构模式。
The fourth section concludes that the double-principal taxes system is the most stable mode after researching on the worldwide double-principal taxes system trend of tax structure. 第四部分对国际上税制结构趋同化向双主体税制发展趋势进行了思考，得出双主体税制结构模式是最稳定的态势的结论。
