With regard to Ethernet media access methods, which of the following are true?（）

A . many B . lot C . much

A . I'm afraid so B . No, I'm sorry not C . I'm afraid not D . It's my pleasure

A . (1) only B . (2) only C . both (1) and (2) D . neither (1) or (2)

A .  The IEEE 802.1Q frame format adds a 4 byte field to a Ethernet frame B .  The packet is encapsulated with a 26 byte header and a 4 byte FCS C .  The protocol uses point-to-multipoint connectivity D .  The protocol uses point-to-point connectivity E .  The IEEE 802.1Q frame uses multicast destination of 0x01-00-0c-00-00 F .  The IEEE 802.1Q frame retains the original MAC destination addre

A . during low loads B . after proper oil viscosity is reached C . during starting D . after cleaning filter

A . Oil is discharged from the impeller through the outlet B . Gravity causes the oil to flow toward the discharge C . The self-priming feature of the centrifugal pump enables it to draw its own suction as it starts D . The discharge capacity varies directly with the speed of the impeller

A . the third largest　 B . the fourth largest C . the fifth largest　 D . the sixth largest

A . implementing the safety and environmental protection policy of the Company B . motivating the crew in the observation of that policy C . designing the procedures for internal audits and management reviews D . issuing appropriate orders and instructions in a clear and simple manner

A . mkvdev -sea ent1 -vadapter ent2 -default ent1 -defaultid 1 B . mkvdev -sea ent1 -vadapter ent0 -vadapter ent2 -default ent1 -defaultid 1 C . mkvdev -sea ent0 -vadapter ent1，ent2 -defaultid 1 D . mkvdev -sea ent0 -vadapter ent1 ent2 -default ent1 -defaultid 1

A . Switches are primarily software based while bridges are hardware based. B . Both bridges and switches forward Layer 2 broadcasts. C . Bridges are frequently faster than switches. D . Switches typically have a higher number of ports than bridges. E . Bridges define broadcast domain while switches define collision domains. F . Both bridges and switches make forwarding decisions based on Layer 2 addresses.

A . The number of collision domains would decrease. B . The number of collision domains would increase. C . The number of broadcast domains would remain the same. D . The number of collision domains would remain the same. E . The number of broadcast domains would increase.

A . 正确 B . 错误

A．complete indifference. B．qualified acceptance. C．skeptical amusement. D．perplexed astonishment.

A．positive B．negative C．indifferent D．critical

A．Neutrino astronomy will supersede all present forms of astronomy. B．Neutrino astronomy will be abandoned if the DUMAND project fails. C．Neutrino astronomy can be expected to lead to major breakthroughs in astronomy. D．Neutrino astronomy will disclose phenomena that will be more surprising than past discoveries. 此题为多项选择题。

Which of the following is correct with regard to stocks？ (i) Stock-outs arise when too little stock is held. (ii) Safety stocks are the level of units maintained in case there is unexpected demand. (iii) A reorder level can be established by looking at the maximum usage and the maximum lead-time. A、(i) and (ii) only B、(i) and (iii) only C、(ii) and (iii) only D、(i), (ii) and (iii)

A．A.No,I can' t B．B.Yes, thanks C．C.I'd love to D．D.It's a pleasure

A．A.No,I have other plans. B．B.No,Idon't like being with you. C．C.Yes, that's very kind of you, thanks.

A．make things bad B．make things good C．make things worse D．make things better

A．I’d love to go B．I’m sorry C．I’d love to D．I’d love