frontier pass

英 [ˈfrʌntɪə(r) pɑːs]

美 [frʌnˈtɪr pæs]

边防通行证；边界通行证

Here are the main idea: Ming dynasty government adopts special frontier policy to set up seven garrisons in the west of Jiayu Pass is just because of its special situation of northwest frontier.
略论清代前期西北边疆的因俗而治政策认为：正是明代特殊的西北边疆形势，才使明政府采取了特殊的边疆政策&设置关西七卫。
Zhaojun going out of the frontier pass made the two nationality of Han and Xiongnu become peaceful and increased the cohesion of the Chinese nation constantly.
昭君出塞是汉匈两族从战争走向和平道路、中华民族凝聚力不断增强的结果；
Laozi was stopped by frontier guards when leaving Hangu Pass for the west, let go after writing down Tao Te Ching.
老子在西出函谷关时，被边防人员拦住，写下了《道德经》后才被放行。
In the past two thousand years, a profound cultural inheritance has been accrued around the literal quotation of Zhaojun going out of the frontier pass.
两千多年来，围绕昭君出塞这个典故形成了丰厚的文化积淀。