当强光照到眼睛时，瞳孔收缩是一种自然反射。

Pupil contraction is a natural ___reflex when bright light hits the eyes.

他的慷慨行为是他善良本性的反映。

His generous act was a ___reflection of his kind nature.

她站在镜子前，欣赏着自己清晰的倒影。

She stood in front of the mirror, admiring the clear ___reflection of herself.