The essence of(74) is the invention of a hierarchical, domain-based naming scheme. It is primarily used for mapping host names and e-mail destinations to IP addresses.

A．DNS

B．NNTP

C．CDP

D．FTP

[单选题]A． caseB． shortC． turnD． essence

[单选题]_____ has made this invention is a remarkable person and worth remenberingA．whoeverB．whoC．no matter whoD．whom

[名词解释] 创意曲（Invention）

[名词解释] 创意曲invention

[主观题]What is the most helpful invention? Do you think?（合并为一句）What__________ __________ __________ __________the most useful invention?

[单选题]The newcommunication system is by no means a [minute] invention.A.smallB.ac

[单选题]Computer Mouse Thebasic computer mouse is______(51)amazingly clever inventi

[单选题]Computer Mouse Thebasic computer mouse is______(51)amazingly clever inventi

[单选题]Computer Mouse Thebasic computer mouse is______(51)amazingly clever inventi

[单选题]Computer Mouse Thebasic computer mouse is______(51)amazingly clever inventi