偷偷的笑

例句：

1. 1. She smiled at the sight of her old friend.
   她看到老朋友时露出了微笑。
2. 2. The teacher smiled at the student who answered correctly.
   老师对答对的学生微笑着。
3. 3. Her smile brightened up the room with its warmth and kindness.
   她的微笑温暖而善良，让整个房间都亮堂起来。