"can I help you"的回答为什么不能用"I don't need your help"来回答?

"can I help you"的回答为什么不能用"I don't need your help"来回答? Can I help you,Andy ?Yes I need your help,Mrs Li.I don't kno Can I help you,Andy?Yes.I need your help,Mrs Li.don't know（ can i help you回答 Stop!I don`t need your help. can i help you的回答 can i help you 的回答 Can I help you?的回答 I'm sorry I can't help you.怎么回答 can I help you 这样回答NO,you can‘t行吗为什么不行 Don't w_ .I can help you. I don't need your help,because I can do it _____