C.ommunication in the Internet works as follows. The (73)layer takes data streams and breaks them up into datagrams. Each datagram is transmitted through the Internet, possibly being fragmented into smaller units as it goes. When all the pieces finally get to the destination machine, they are reassembled by the(74) layer into the original datagram. This datagram is then handed to the transport layer, which inserts it into the receiving process' input stream.
A.n IP datagram consists of a header part and a text part. The header has a (75) part and a variable length optional part.(71) A. IP (Internet Protocol)
B. IP (Interworking Protocol)
C. TCP (Transport Control Protocol)
D. TCP (Transfer Communication Protocol)(72) A. best-quality
B. quality-guaranteed
C. connection-oriented
D. best-efforts(73) A. data link
B. transport
C. network
D. application(74) A. data link
B. transport
C. network
D. application(75) A. 40-byte fixed
B. 64-byte fixed
C. 20~64 bytes variable
D. 20-byte fixed
[单选题]The author holds that______.A.mortality rates in developing countries have been brought down by a number of forcesB.medical innovations are the only way to reduce mortality rates in developing countriesC.the upgrading of hygiene and sanitation has pl
[单选题]There is ________ in the holds keeping eyes opened to prevent theftA.watchmanB.watchmenC.a watchmenD.a watchman
[单选题]We hadn't realized that there would be a power cut so we are astonished whe
[单选题]On the whole, the passage is about______.A. how to start a universityB. the world-famous colleges in AmericaC. how colleges have changedD. what kind of lesson each college teaches
[单选题] __74___ Encourage the whole
[主观题]Rosenberg holds that public advocates should[A] recruit professional advertisers[B] learn from advertisers’ experience[C] stay away from commercial advertisers[D] recognize the limitations of advertisements
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[主观题]The area where the air carrier holds the accepted cargo is also restricted area.此题为判断题(对,错)。
[单选题]The semantic triangle holds that the meaning of a word ( )A.is interpreted