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名 border，boundary，place，area，condition ；

[例句] 貨幣兌換成本仍是跨境貿易的最大障礙之一。 Currency-conversion costs remain one of the biggest obstacles to cross-border trade.

[例句] 我方飛行員飛越敵境之后,我們向他詢問情況. We debriefed our pilot after he had flown over the enemy's land.