duke收到ad后的准备工作求问.

求同收到duke  ee ms 的同学，如果要accept需要做什么工作。This offer of admission is valid until April 15, 2015, or within 15 days of the date of this letter, whichever is later.这句话对于我来说就是415截止decision对吧？
Print a copy of the decision letter for your records. This is especially important if you are an international student in need of a visa.网申admitted student里有这么一句，这个decision letter在哪里找啊？
除了以上这些还有啥需要注意的？
祝各位offer多多