防御工事的用法和樣例：
例句
-
這些防御工事都是上次戰爭時(shí)修筑的。
These fortifications were all built during the last war. -
敵人沖破了我們的防御工事。
The enemy brushed aside our defences. -
防御工事已筑好，準備對付敵人進(jìn)攻。
The defences are kept in readiness for any enemy attack. -
這些防御工事是上次戰爭時(shí)修建的。
These fortifications were built during the last war.
