Mary was graduated from Oxford. She graduated from Harvard ,第一句有was ,第二句为什么没有呢?这两句我看意思一样呀

The verb graduate has denoted the action of conferring an academic degree or diploma since at least 1421.Accordingly,the action of receiving a degree should be expressed in the passive,as in She was graduated from Yale in 1998.This use is still current,if old-fashioned,and is acceptable to 78 percent of the Usage Panel.In general usage,however,it has largely yielded to the much more recent active pattern (first attested in 1807):She graduated from Yale in 1998.Eighty-nine percent of the Panel accepts this use.It has the advantage of ascribing the accomplishment to the student,rather than to the institution,which is usually appropriate in discussions of individual students.When the institution's responsibility is emphasized,however,the older pattern may still be recommended.A sentence such as The university graduated more computer science majors in 1997 than in the entire previous decade stresses the university's accomplishment,say,of its computer science program.On the other hand,the sentence More computer science majors graduated in 1997 than in the entire previous decade implies that the class of 1997 was in some way a remarkable group.•The Usage Panel feels quite differently about the use of graduate to mean “to receive a degree from,” as in She graduated Yale in 1998.Seventy-seven percent object to this usage.
大概意思就是
Mary was graduated from Oxford.把功劳归学校.没有学校的努力,她不可能成功的毕业
She graduated from Harvard 把功劳归人.没有她本人的努力,她不可能毕业.