关于确认录取AD的疑问

neroliangUID: 2563612

昨收到NUS小米来的信,让我填写两份表,分别是:
Reply on Offer of Admission 和 Declaration of Subsidy received.
其中有个问题是:
Have you been offered admission to other graduate programmes in this University of another programme?本人情况是已经有NUS其他学院的Offer和NTU某些学院的Offer,是否必须如实填写?
另外一个相关问题是, "You are required to produce documentary evidence that you have since withdrawn from all other programmes.
如果我对前一问题的回答是肯定的,这里需要提供材料吗?什么文件能证明我已经放弃其他学位的录取机会?