A teacher can be [fairly] sure about the academic progress of the students, but not [as] sure about their moral development. [The reason for this is] that society is a big dyeing pool in which one's being dyed into a certain color is the result of many factors of which family and many other things also have a role to play. [Your meaning is clear enough in the original. I just made some small changes. 我希望我帮助]

If you want this done then post it in your notebook. Lots of people there will help you with your homework.