sandbag bunker

例句：

1. 1.The soldiers dug a sandbag bunker to protect themselves from the enemy's attack.
   士兵们挖了一个沙袋堡垒来保护自己免受敌人的攻击。
2. 2. The engineers used sandbag bunkers to reinforce the weak points in the wall.
   工程师们使用沙袋堡垒加固了墙的薄弱环节。
3. 3. During the war, many people used sandbag bunkers as shelters to escape from the bombing.
   在战争中，许多人使用沙袋堡垒作为避难所来躲避轰炸。