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.

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几十年来，地震工程师的目标看起来如此直接：防止建筑物倒塌。

For decades the goal of seismic engineers has seemed straightforward: Prevent building collapse.

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几十年来，地震工程师的目标看起来如此直接：防止建筑物倒塌。

For decades, the goal of seismic engineers has seemed straightforward: Prevent building collapse.

youdao