It's important to backout Beijing's wall in the capital's history. 拆除城墙是首都发展史上的重大事件。
In the total process of the construction project, the risk has an important influence on the life-cycle cost from the decision-making and the running phase to the backout phase. 摘要在建设项目从决策设计到实施运行直到拆除的全过程中,风险对全生命周期的造价影响贯穿其中。