援军的用法和样例：
例句
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由于敌军进攻加剧，越来越多的援军被派遣上前线。
As enemy attacks increased, more and more reinforcements were dispatched to the front. -
密集的迫击炮火力从这些阵地射向由山谷那边上来的援军。
From these positions mortar fire was rained down upon reinforcements moving up through the valley. -
请派援军来——敌人在大举进攻了。
Send for reinforcements-the enemy are attacking in strength. -
战士们拼死坚守阵地，直到援军到来。
The soldiers held the fort desperately till reinforcement arrived.
