拱心石（keystone）又名拱顶石，是拱门或拱道建筑，在最顶端要有一块石块来契合两边的石头并承受其压力。
建筑学中，拱道或门口的拱心石，是把建筑整体连接在一起来防止它倒塌的石头。
In architecture, a keystone in an archway or doorway is the stone that holds the whole thing together, and keeps it from collapsing.
但有一个人一如既往地稳定，成为支撑桥梁的拱心石——他就是维迪奇。
But if there's been one constant, the keystone holding up the bridge, it's Vidic.
计划中的大号拱心石石油管道将用于运输产自加拿大油沙的重原油。
The proposed Keystone XL pipeline would carry heavier crude oil produced from tar sands in Canada.
应用推荐