短语词组短语hollow arch -gravity dam 空腹重力拱坝gravity arch dam 重力拱坝gravity -arch dam 重力拱坝RCC Gravity -Arch Dam 碾压混凝土重力拱坝concrete gravity -arch dam 混凝土重力拱坝vierendeel gravity -arch dam 空腹重力拱坝 返回 arch gravity dam