If the true dip line of one or two joint planes plot within a sliding zone of double-faced slope, a double-faced sliding failure can be possible.

如果有一两个节理面真倾向线落在滑动区内，滑动破坏才可能发生。

youdao

Every rule you learned about the true stuff of business--growth, operations and profit--begins to dip and flutter like a knuckleball when YourWorstNightmare.com walks onto the field.

FORBES: The Web'S Fog Of War