战国期间(公元前5世纪- 221年)，齐、燕、赵修建大量城墙保卫其边境。

During the Warring states Period (5th century BC-221 BC), the states of Qi, Yan and Zhao all constructed extensive fortifications to defend their own borders.

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在这里，我没有看到北燕南飞前在电线上的集结，也没有看到到寒气逼人的树挂冰霜，更没有看到耀眼纯洁的皑皑白雪。

Here, I do not see North Yannan Fei on the wire before the assembly, did not see the cold pressing of the trees hanging frost, but do not see the dazzling purity of snow.

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在从公元前5世纪至公元前221年的战国时期，秦、魏、赵、齐和燕各国建立广泛的防御工事来保卫自己的边界。

During the Warring states Period from the 5th century BC to 221 BC, the states of Qin, Wei, Zhao, Qi and Yan all constructed extensive fortifications to defend their own borders.

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