no problem
是一个口语意思是说“没问题”
回答对方的thank you 有以下这些
不用谢.
You're welcome.
不用谢.
You are welcome.
不用谢.
It was my pleasure.
谢谢.不用谢.
Thanks a lot.Don't mention it.
谢谢.不用谢.
Thank you. Not at all.
谢谢.不用谢.
Thank you. You are welcome.
那没什么,不用谢.
That's all right,you're welcome.
算不了什么,不用谢
Forget it
不用谢,我不要任何报酬,不用记在心上.
No thanks,I don't want any payment - skip it.
我知道你很感激,不过那没什么,不用谢.
I know you're grateful,but that's all right,any time.
以上这些都是谦虚的回答!