jiān gù de fáng xiàn / chéng wéi / yán hǎi chéng shì / dǐ yù / fēng bào / hé / wài dí / de / píng fān坚固的防线成为沿海城市抵御风暴和外敌的屏藩。The strong defensive line became a protective shield for the coastal city against storms and foreign enemies.