食盐在那个时代是极贵重的商品，因此，古城四周为何会环绕着坚实的防御性石墙就有了合理的解释。

Salt was a hugely valuable commodity at the time, which experts say could help to explain the huge defensive stone walls which ringed the town.

youdao

食盐在那个时代是极贵重的商品，因此，古城四周为何会环绕着坚实的防御性石墙就有了合理的解释。

Salt was a hugely valuable commodity at the time, which experts say could help to explain the huge defensive stone walls which ringed the town.

youdao