16.Building Dams

Controlofhislife-sustainingwatersupplyhasalwaysbeenoneofman’sprimaryconcerns.For5,000years,damshavebeeninstrumentalinthiscontrol,beingusedtoavertfloods,divertrivers,storewater,andirrigateland.Manyoftoday’sconstructionsfulfillthesesameage-oldfunctions;dams ......（本文共 5920 字 ）     [閱讀本文] >>