那位老人展现了真正的待客之道，不仅邀请陌生人进屋休息，还为他准备了热茶和食物。

The old man showed true ___xenia by inviting the stranger inside and offering him warm tea and food.

研究人员发现，花粉通过花粉效应直接改变了苹果种子的颜色。

Researchers found that ___xenia directly altered the color of apple seeds through pollen effects.