This is the 1953rd most frequent Chinese word.
替
"替" means "to replace," "substitute," or "on behalf of."
In this sentence, '替' is used to indicate someone performing an action on behalf of another person.
他替我完成了工作。
He completed the work on my behalf.
Here, '替' shows that the action is done for the benefit of someone else, in this case, students.
我替学生们解决了问题。
I resolved the problem for the students.
'替' in this example is used to ask someone to do something on behalf of another person.