Which is the second layer from the bottom in Open System Interconnection Reference Model? (71)．(71) A. Application

B．Data link

C．Network

D．Session

[单选题]Which sentence in the second paragraph is the topic sentence?A． Lyne was a headmaster.B． A lot of kids had chains around their necks.C． I was constantly telling them to put inside their shirts.D． They were house keys.

[单选题]A．t which layer of the OSI model does the protocol that provides the information displayed by the "show cdp neighbors" command operate?A．TransportB．PhysicalC．ApplicationD．Data linkE．Network

[单选题]From fetus to adult，the Second Growth Spurt appears in（）。A .prenatal periodB .infant and toddle periodC .childhoodD .puberty

[单选题]Which OSI layer does a Router operate at?A．the Physical LayerB．the Data Link LayerC．the Transfer LayerD．the Network Layer

[单选题]Which OSI layer does a bridge operate at?A．the Physical LayerB．the Network LayerC．the Transport LayerD．the Data Link Layer

[单选题]We may infer from the second paragraph thatA．DNA technology has been widely applied to history research.B．in its early days the U.S. was confronted with delicate situations.C．historians deliberately made up some stories of Jefferson's life.D．politic

[单选题]F．rom the second paragraph, we can see that in the early years,______.A． those colleges and universities were the sameB． people, young or old, might study in the collegesC． students studied only some languages and scienceD． when the students finished

[单选题]We may infer from the second paragraph that[A] DNA technology has been widely applied to history research.[B] in its early days the U.S. was confronted with delicate situations.[C] historians deliberately made up some stories of Jefferson’s life.[D]

[单选题]is a six bytes OSI layer 2 address which is burned into every networking device that provides its unique identity for point to point communication。A．The virtual addressB．The subnet addressC．The MAC addressD．The IP address

[单选题]28． From the second paragraph(段) ,we know the modern trains have_________ ．A． the slower ways of travellingB． few travelersC． comfortable seats and dining carsD． comfortable seats