她突然的情绪爆发被认为是非理性行为。

Her sudden outburst was dismissed as mere ___irrational behaviour.

他对鸽子有一种非理性的恐惧，尽管它们并无害处。

He has an ___irrational fear of pigeons, despite their harmlessness.

这是一种非理性的恐惧，但要向一个五岁的孩子解释清楚却很困难。

It was an ___irrational fear, but try to explain this to a five-year-old.