unselfishly

例句：

1. 1. He gave up his seat to the elderly man in front of him.
   他放弃了自己前面的座位给一位老人。
2. 2. She is always unselfishly helping others without expecting anything in return.
   她总是无私地帮助别人，不求回报。
3. 3. The teacher praised the student's unselfish behavior and encouraged him to continue being likethis.
   老师表扬了学生的无私行为，并鼓励他继续这样做。