回复：f1申请批准，但旧的I－94卡原件没寄回，不知道为什么？需要申请取回吗？请指教，多谢！！

You do not need that I-94 anymore because it was replaced by the new I-94 with your F1 approval notice. But you should keep the photocopy of the old I-94 for future possible use to prove your valid status during this period of time.