For each blank, choose the best answer from the four choices and write down on the answer sheet.
(11) is a protocol that a host uses to inform a router when it joins Or leaves an Internet multicast group.
(12) is an error detection code that most data communication networks use.
(13) is an interior gateway protocol that uses a distance vector algorithm to propagate routing information.
(14) is a transfer mode in which all types of information are organized into fixed form cells on an asynchronous or non-periodic basis over a range of media.
(15) is an identifier of a web page.

A．OSPF

B．RIP

C．RARP

D．BGP

下列一张报关单中有20个已填（包括空填）栏目（标号A～T），请指出其中填制错误。

资料1：

南京某进出口公司出口小五金工具一批。外汇核销单号：32C199255；出境货物通关单号：310050204415308000。

该批货物的法定计量单位分别为：

钢卷尺：个；攻丝工具：千克/个；锉刀：千克/个

资料2：

中华人民共和国海关出口货物报关单

资料3:

INVOICE

资料4：

PACKING LIST