用于对方道谢:It is nothing. It doesn't matter. (It is) No matter. You are welcome. Don't mention it. Not at all. That's all right. (It's) My pleasure. That's OK.No problem. It's a pleasure.
用于对方道歉:Forget it. That's OK. That's all right.No problem. It doesn't matter. (It is) No matter. Never mind. It is nothing.