第二章主要研究酉系统的膨胀性质。
They constitute a unitary system, in which all the qualities interact with and affect each other.它们构成了一个有机的统一体,彼此之间相互作用、相互影响。
The situation in many of Russia's unitary system towns is highly problematic due to their inflexibility and uncompetitiveness.由于缺乏灵活性、不具竞争力,俄罗斯的许多单一制城市面临严重问题。