Yesterday I had a word with the CEO of the company who used to teach at Beijing Universi

问题补充：

Yesterday I had a word with the CEO of the company, who used to teach at Beijing University．

A. one

B. the one

C. that

D. it

答案：

A. one

(答案→)B. the one

C. that

D. it

解析：the one作同位语，特指the CEO 0fthe company。