城中街道不宽，这样街上的建筑互相遮阴，而且房屋的墙和房顶都各自发挥散热作用。

Streets are narrow so buildings shade each other, and the walls and roofs of buildings will do their bit to shed heat too.

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两座敌楼相隔不超过120米，敌楼之间就可以起到互相保护的作用了。

At intervals of no more than 120 meters, the adjacent two ramparts were able to protect each other most effectively.

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