阅读对话，判断下面句子的正误。

Mike: Good morning, Mr Wang.

Mr Wang: Good morning, Mike.

Mike: This is my friend, Sarah. Sarah, this is our teacher, Mr Wang.

Sarah: Nice to meet you, Mr Wang.

Mr Wang: Nice to meet you, too. Are you a new student?

Sarah: Yes, I am.

Mr Wang: Where are you from?

Sarah: I'm from the USA.

Mr Wang: Oh! Welcome.