根据下面的文字资料回答 68~72 题For each blank.choose the best answerfrom the four choices
(1 )is a protocol that a host uses toinform. a router when it joins or leaves an Internet muhicast group.
(2 ) is an error detection code that most data communication networks use.
(3 )is an interior gateway protocol that uses a distance vector algorithm topropagate routing information.
(4 )is a transfer mode in which all types of information ate organized intofixed form. cells onan asynchronous or non-periodic basis over a range of media.
(5 )is an identifier of a web page.
第68题:文中(1 )处正确的答案是()。
A.SMTP
B.ICMP
C.RARP
D.IGMP