在不明飞行物学中，人类与外星任何形式的接触都被称为第五类接触。

In Ufology , any extraterrestrial contact initiated by humans is known Close Encounter of the Fifth Kind.

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雅克布斯教授是飞碟学方面的专家，他研究不明飞行物已有20多年。

Professor Jacobs is an expert in Ufology and has been studying UFO's for over 20 years.

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听看学汤姆：你相信有不明飞行物吗？

Tom : Do you believe in UFOs?

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听看学汤姆：你相信有不明飞行物吗？

Tom : Do you believe in UFOs?

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