名 border，boundary，place，area，condition ；

[例句] 货币兑换成本仍是跨境贸易的最大障碍之一。 Currency-conversion costs remain one of the biggest obstacles to cross-border trade.

[例句] 我方飞行员飞越敌境之后,我们向他询问情况. We debriefed our pilot after he had flown over the enemy's land.