看到孩子们快乐地玩耍，她忍不住露出了微笑。

She couldn't help but ___smile when she saw the children playing happily.

她的微笑总是能让人心情变好。

Her ___smile always brightens people's day.

老师看到学生们认真完成作业时露出了微笑。

The teacher ___smiled when she saw her students diligently completing their homework.