Crossing your arms is a protective posture.

双臂交叉是一种防卫姿态。

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The video showed the gorilla sometimes standing over the boy in what appeared to be a protective posture, but then darting through the shallow moat, dragging the child behind him.

视频显示，那只大猩猩有时候会用看似是保护姿态的姿势站在小男孩旁边。但随后，它便在浅水沟里猛冲，身后拖着小男孩。

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The acronym stands for Mission Oriented Protective Posture, with levels of zero through four.

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