1 sentence

1. 人们从前在城镇四周筑坚固城墙以防御敌人。

   rén​men cóng​qián zài chéng​zhèn sì​zhōu zhù jiān​gù chéng qiáng yǐ fáng​yù dí​rén.

   People used to build strong walls round their towns as a defense against enemies.

   Source: UM-Corpus: Education