能够识别抗原的细胞或物质是（）①吞噬细胞②T细胞③B细胞④记忆细胞⑤浆细胞⑥效应T细

Questions from 31 to 35 are based on the following passage:

　　The exporter, as drawer of a draft (bill of exchange), hands the draft to his bank, the remitting bank, who in turn forwards it to the buyer through a collecting bank in the buyer’s country. A draft (also called a bill) is a written order to a bank or a customer to pay someone on demand or at a fixed time in the future a certain sum of money. If shipping documents accompany the draft, the collection is called “documentary collection.”

　　Documentary collection falls into two major categories: one is documents against payment(D/P); the other, documents against acceptance (D/A).

　　Documents against payment, as the term suggests, is that the collecting bank will only give the shipping documents representing the title to the goods on the condition that the buyer makes payment.

　　Where the paying arrangement is D/A, the collecting bank will only give the buyer the shipping documents after buyer’s acceptance of the bill drawn on him, i.e. the buyer signs his name on the bill promising to pay the sum when it matures. In return he gets what he needs – the shipping documents.

　　Under D/A, the seller gives up the title to the goods – shipping documents before he gets payment of the goods. Therefore, an exporter must think twice before he accepts such paying arrangement.

Under D/A , the importer can gets what he needs – the shipping documents only by（）.

A．showing the bill of lading　　

B．paying in cash

C．making acceptance of the bill of exchange

D．paying the bill of exchange

某卵石地基采用重型圆锥动力触探试验，实测其锤击数为22，钻杆杆长L=8.0m，该地基卵石的密实度为（）。

A.密实

B.中密

C.稍密

D.松散

60年代末出现的数据库技术，当时主要由于（）

A.工程技术

B.科学研究

C.商务数据处理

D.行政管理

世界第三大洋是什么洋？

MSN Messenger与QQ等聊天工具相同的功能是（）

A、MSN Messenger中与联系人的对话是连续的

B、MSN Messenger可改变用户自己的状态

C、MSN Messenger可传递图片文件

D、MSN Messenger可进行语音对话