区域经济一体化有多种形式,从贸易安排的水平看,可以分为五类或五个阶段:优惠贸易安排(preferential trade arrangements)、自由贸易区(free trade areas)、关税同盟(cus-toms unions)、共同市场(common market)和经济同盟(economic unions)。具体到中俄区域经济合作,可分为三个层次:第一个层次是指贸易和投资的便利化,其具体内容是两国相 There are many forms of regional economic integration. From the perspective of trade arrangements, they can be divided into five or five stages: preferential trade arrangements, free trade areas, cus-toms unions, common markets and economic unions. Specific to China-Russia regional economic cooperation can be divided into three levels: the first level refers to the facilitation of trade and investment, the specific content of the two countries phase