有关S/L合同条款的翻译问题Thebuyershouldopen

有关S/L合同条款的翻译问题Thebuyershouldopen: The buyer should on through a bank acceptable to the seller an irrevocable Letter of Credit at 30 days after sight to reach the seller 30days before the month of shipment valid for negotiation in China until the 15th day after the date of shipment 请问这句话是; The buyer should open(买方应该开立） through a bank （通过银行）acceptable（可接受的） to the seller（给卖方） an irrevocable Letter of Credit（不可撤销的信用证） at 30 days after sight （见票后30天）to reach the seller（到达卖方） 30days before the month of shipment（装运期那个月前的30天） valid for negotiation（有效议付） in China （在中国）until the 15th day after the date of shipment （直到装运后的第15天）。能顺成一句话 :买方应在装运月份之前三十天通过银行开给卖方一个所能接受的不可撤销的信用证,该信用证的付款为见票后30天, 装运后的15天内在中国议付有效。