@cindyzhao,
Most of the frequent posters on A2K are not teenagers anymore.
I don't know about them but I guess, like me, that they are not used to the subtle intricacies and different meanings of the daily language of adolescents.
As so, I take that when you call someone stupid, it's what you mean.
It can be perceived as an offense.
I can be wrong though.
However, I welcome you to A2K. If I can be of any help, I'm here for you.