Question

Which dynasty built protective walls along the northern border.

Answer 1

The Qing Dynasty of ancient China built the Great Wall of China along the northern border as a way of preventing outsiders from attacking .

Step-by-step explanation:

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Answer 2

The Great Wall of the Qin Dynasty (221BC-207 BC) was built during the reign of Emperor Qin Shi Huang, along the country's northern border to prevent the invasion of Huns.