About _________ of the teachers in tour school were born in ________.

A．two thirds, 1970

B．two thirds, the 1970s

C．two third, 1970s

D．two third, the1970

企业年金是指企业及其职工在依法参加基本养老保险的基础上，自愿建立的补充养老保险基金。