Ответ:
You: Good morning, Mrs Brown. This is my English friend, Alex.
Teacher: Oh, hello, Alex!
You: Alex, this is my teacher, Mrs Brown.
Your friend: Hello, Mrs Brown. Nice to meet you.
Teacher: Nice to meet you too, Alex.
You: Good morning, Mrs Brown. This is my English friend, Alex.
Teacher: Oh, hello, Alex!
You: Alex, this is my teacher, Mrs Brown.
Your friend: Hello, Mrs Brown. Nice to meet you.
Teacher: Nice to meet you too, Alex.