加定冠词the。
n. 主席，会长董事长
The chairman also attended the award ceremony and made an opening statement.
主席也出席了这次颁奖会，还做了开场白。
I was appointed as the chairman of the student union of our school.
我被任命为我们学校学生会的主席。
He has served as the chairman of the College Debate Contest for three years.
他连续三年担任校园辩论赛主持人。
