城墙

gōng pò chéng qiáng

攻破城墙

breach the city walls

jiàn zào chéng qiáng

建造城墙

build a wall

wǒ men zài chéng qiáng shang xíng zǒu

我们在城墙上行走。

We walked along the top of the city walls.

gāi chéng qiáng hěn hòu

该城墙很厚。

The city wall is very thick.