没有人是为了发财才当老师的。人们之所以选择教师这个行业主要是为了做一些对社会更有益的事情。

A. arrange a face-to-face meeting for their child and his/her friends on the net
B. never give out the personal information like home address in a public message
C. treat personal computers as electronic babysitters of their child
D. be indifferent to any offers that even don’t involve them sending credit-card information