听力原文:For the last 12 of his 40 years of teaching, Professor Thomas Armstrong has serve
听力原文: For the last 12 of his 40 years of teaching, Professor Thomas Armstrong has served as Chair of the History Department. He has written books on many topics, such as Liberals vs. Conservatives and 18th Century Canadian History. He is an expert on early Canadian Studies and has a bachelor's degree from Antioch University. Even after 40 years, Professor Armstrong continues to lead the way for future academics. Join me in welcoming our distinguished guest speaker, Professor Thomas Armstrong.
What is the purpose of this speech?
A.To inform. students
B.To introduce a speaker
C.To announce a new class
D.To announce a retirement