I don 't know the man. The man is talking with our headteacher(改为含有定语从句的复合句)
I don't know the man talking with our headteacher.
David feels very proud to be a member of the school volleyball (队).
It is not (礼貌的) to make too much noise while eating or drinking.
Lulu's best friend never gives up her (梦想) of being a teacher.
If you would like to (讨论) the matter further,please call me.
I've (已经) seen that film,so I'd rather see another one.