根据短文，选择合适的单词填入短文下面的横线中。

    Last Sunday, Dad me to the park. In the park, I a little girl crying. She us she could not find her parents. We helped her to look for her parents. After a while, we found her parents. When the girl saw her parents, she to them. The girl was happy, and her parents happy, too. At last they thanked us and we good bye to each other. I felt very happy to help others.