[他们是无私的] 用英语怎么说

They never complained

To students he sacrificed his wonderful time

They are the greatest

[他们是无私的] They are selfishless.
[他们从来不抱怨]They never complain.
[为了学生牺牲了自己的美好时光]They sacrifice the best years of their life for the students.
[他们是最伟大的]They are the greatest people.

他们从来不抱怨--They always did not complain .
为了学生牺牲了自己的美好时光--Has sacrificed own happy time for the student .
他们是最伟大的--They are greatest .