Common focus point (CFP) migration based on the equal travel-time principle is a kind of pre-stack depth migration method through focusing in both emission and detection.

共聚焦点(CFP)偏移是基于等时原理，通过激发聚焦和检波聚焦的双聚焦实现叠前深度偏移的地震成像方法。

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At the start, at least, these other parents seem like nice enough people, but as time goes on and travel leagues get formed, the social dynamic can turn into something equal to the age level of the children playing.

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