防禦工事的用法和樣例：
例句
-
這些防禦工事都是上次戰爭時修築的。
These fortifications were all built during the last war. -
敵人衝破了我們的防禦工事。
The enemy brushed aside our defences. -
防禦工事已築好，準備對付敵人進攻。
The defences are kept in readiness for any enemy attack. -
這些防禦工事是上次戰爭時修建的。
These fortifications were built during the last war.
