Passage 1
For my proposed journey, the first priority was clearly to start learning Arabic. I have never been a linguist. Though I had traveled widely as a journalist, I had never managed to pick up more than a smattering of phrases in any tongue other than French, and even my French, was laborious for want of lengthy practice. The prospect of tackling one of the notoriously difficult languages at the age of forty, and trying to speak it well, both deterred and excited me. It was perhaps expecting a little too much of a curiously unreceptive part of myself, yet the possibility that I might gain access to a completely alien culture and tradition by this means was enormously pleasing.
I enrolled as a pupil in a small school in the center of the city. It was run by a Mr Beheit, of dapper appearance and explosive temperament, who assured me that after three months of his special treatment I would speak Arabic fluently. Whereupon he drew from his desk a postcard
A. The writer's intended journey created particular difficulties in his lemming of Arabic.
B. The reading and writing of the Arabic script gave the writer lasting pleasure.
C. The writer found learning Arabic was a grueling experience but rewarding.
D. The writer regarded Ahmed's praise of his pronunciation as tongue-in-cheek
2001年10月，法国某公司(卖方)与中国某公司(买方)在上海订立了买卖200台电子计算机的合同，每台CIF。上海1000美元。以不可撤销的信用证支付，2001年12月在马赛港交货。2001年11月15日，中国银行上海分行(开证行)根据买方指示向卖方开出了金额为20万美元的不可撤销的信用证，委托马赛的一家法国银行通知并议付此信用证。2001年12月20H．卖方将200台计算机装船并获得信用证要求的提单、保险单、发票等单据后，即到该法国议付行议付。经审查，单证相符，银行即将货款议付给卖方。与此同时，载货船离开马赛港10天后，由于在航行途中遇上特大暴雨和暗礁，货船及货物全部沉人大海。此时开证行已收到了议付行寄来的全套单据，买方也已得知所购货物全部灭失的消息。中国银行上海分行拟拒绝偿付议付行已议付的货款，理由是其客户不能得到所期待的货物。根据国际贸易惯例．现问：
本案中信用证要求的提单、保险单、发票等单据中属于官方单证的是（）。我来回答:
