网申时候有说学校要求必须是院长？

今天看学校的时候发现有学校要求是：
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Two sets of recommendation letter and  One from a current dean or a current head of the department, where you belong to or graduated from, and the other from your supervisor.

需要其中一封必须是current dean啊？话说我跟head of dean没有交集，而且这个dean到底指的是谁啊？大家有碰到过吗？


另外Those who have not yet been conferred with the diplomain the present course of study at the time of application are requested to submit anauthorized statement of anticipated graduation.
这个authorized statement又是什么东东？

另外对于Official Diplomaor graduation certificate学校要求

Please do not send the original.

One with the certified seal/stamp of the university yougraduated from and six copies of it

Doctoral course applicants must submit both Bachelor's and Master's diplomas& certificates.

额是有本科的diploma了，但是又不让我发原件（也不可能发过去），难不成就是复印件装到信封里面？难不成本科的diploma还可以官方开很多份吗？还是复印件上面再盖学校的章就行了啊？