请问IT/IC/IS各有什么区别?

请问IT/IC/IS各有什么区别? IT销售和IC销售有什么区别 音响IC和电源IC有什么区别? 请问IC和IT的区别是什么拜托各位大神 EQ IQ IC IT各代表什么 is 和is it 有什么区别 请问And it is called chemical change.和And it called chemical change有什么区别? 请问And it is called chemical change.和And it called chemical change有什么区别? IC 与芯片的区别IC 就是芯片吗?如果不是,它们有什么区别? 请问,There is difficulty in doing句型和It is difficulty to do ,有什么区别? 我没读过什么书,想理解有下,IC和IT有什么区别?我想了解IT和TC有何区别?还有SD是什么? ic卡,磁条卡价格有什么区别?各有什么优势 It is partly phonet ic. IC、IC集成电路、集成电路三者有什么关系,又有什么区别? Isn't it 和 is it区别有什么区别 请问这两句英语有什么区别?it is like being an old man.it is like an old man. it is funny 和it is fun有什么区别? it is funny 和it is fun有什么区别?