Secondly,how could the ancient working people to transport so large and heavy stones,bricks and lime to the dangerous top of the walls since there were no modern machines?

• 其二，长城建筑在险峻的山脉之巅，在没有现代化机械的古代，人们是如何将数量如此之大的石料、砖瓦和石灰搬运上去的呢?