defend oneself against the enemy

• 防御敌人

defend oneself against the enemy的用法和样例：

例句

1. Be careful to defend yourselves against the enemy.
   要小心防御敌人。
2. People used to build strong walls round their towns as a defence against enemies.
   人们从前在城镇四周筑坚固城墙以防御敌人。