支付条款在函电中的拟定 — 国际贸易填空题
题目
我方与买方成交一批货物，合同规定：签约后买方先以电汇支付30%预付款，余款70%凭不可撤销即期信用证支付，信用证须在装运期前25天开抵卖方。现需在给买方的确认函中补全支付条款：'Payment shall be made as follows: 30% of the contract value shall be remitted by T/T in advance after signing the contract, and the remaining 70% shall be paid by an ______ L/C at ______, which must reach the seller ______ days before the shipment date.' 依次填入的三个词/短语为：___。