1、长城的导游词：the great wall of china is a series of stone and earthen fortifications in northern china, built originally to protect the northern borders of the chinese empire against intrusions by various nomadic groups。
2、several walls have been built since the 5th century bc that are referred to collectively as the great wall, which has been rebuilt and maintained from the 5th century bc through the 16th century。
3、one of the most famous is the wall built between 220–206 bc by the first emperor of china, qin shi huang. little of that wall remains; the majority of the existing wall was built during the ming dynasty。