根据以下要求生成一段话：需输出4行，从上到下每行句子的字数依次分别为9、11、13、7；必须包含且仅包含一个“hello”单词；语气正式。

Welcome!
Greetings and hello.
We are glad to see you here.
Thank you.
user
Welcome!
Greetings and hello.
We are glad to see you here.
Thank you.
assistant