有关英语现在完成时的since从句的翻译！

有关英语现在完成时的since从句的翻译！ 关键要理解Was在句中所起到的时态功用。copy
since he graduated form Yale. 自从从耶鲁大学毕业zhidao
since he was a student at Yale.自从他不是耶鲁的学生了（有可能是毕业，有可能是肄业...）
Since I was ill 不再生病（病好了）=since I recovered 病愈
举个例子 She was beautiful.