知识贝壳
知识贝壳
所属栏目：建筑施工英语
Tunnelingwasprobablyoneofmansearliestexercisesinthefieldofcivilengineering.TheancientEgyptiansareknowntohavebuilttunnelsfortransportingwaterandforuseastombs.TheEgyptiansalsoundertookminingoperations,cuttingdeeptunnelstoexcavatecopperores.Todaytunnelsareus ......（本文共 6317 字 ） [阅读本文] >>