A PC on a network segment sends data to another PC on a diff

胎儿肺成熟PC/S比值应达到

A、PC/S≥2.0

B、PC／S2.0

D、PC/S1.5～1.9

E、PC／S<1.9

A.data，packet，frame，segment，Bit

B.data，packet，segment，frame，Bit

C.data，segment，frame，packet，Bit

D.data，segment，packet，frame，Bit

从供选择的答案中选出应填入英语文句中()的正确的答案。

PCs originated as stand-alone (A), however, in recent years many have been (B) to Local Area Networks (LANs). In a LAN, the data and usually the user application reside on the File Server, a PC running a special Network Operating System (NOS) such as Novell's NetWare or Microsoft's LAN Manager. The File Server manages the LAN users' shared access to data on its hard (C) and frequently provides access to other shared resources, such as printers. While a LAN enables users of PC-based databases to share (D) data files, it doesn't significantly change how the DBMS works; all the actual data (E) is still performed on the PC running the database application.

A～E: ① calculating ② common ③ connected ④ disks

⑤ displayed ⑥ systems ⑦ primers ⑧ processing

⑨ some ⑩ workstations

A.NAT

B.IDS

C.NMAP

D.DMZ

● Personal firewall is a technology that helps __(66)__ intruders from accessing data on your PC via the Internet or another network, by keeping __(67)__ data from entering or exiting your system.

Hackers do not just target national security organizations for __(68)__: They want your tax returns, network passwords, or bank account numbers. And you do not want the FBI kicking in your door because someone hijacked your PC to __(69)__ in the latest denial-of-service attack on the Internet. Now that “always-on” broadband connections such as cable modems and digital subscriber line are becoming more popular, home users are at risk. Fortunately, you can protect your data.

Firewalls can block __(70)__ attacks and protect your PC from outside threats.

(66)

A. allow

B. prevent

C. invite

D. get

(67)

A. authorized

B. refused

C. denied

D. unauthorized

(68)

A. attacks

B. aggression

C. help

D. repair

(69)

A. enlist

B. go to

C. participate

D. attach

(70)

A. malicious

B. friendly

C. neighborly

D. goodwill

Ⅰ型遗传性PC缺陷症是指

A、PC:A(活性)下降，PC:Ag(抗原)正常

B、PC:A(活性)下降，PC:Ag(抗原)下降

C、PC:A(活性)正常，PC:Ag(抗原)正常

D、PC:A(活性)正常，PC:Ag(抗原)下降

E、PC:A(活性)下降，PC:Ag(抗原)增加

In advanced PC bus or local bus,(18)has the fastest data throughput.

A．EISA

B．MCA

C．PCI

D．ISA

While troubleshooting a connectivity problem on the network, you issue the ping command from your PC command prompt, but the output shows "request times out."

At which OSI layer is this problem associated with?

A．The data link layer

B．The application layer

C．The access layer

D．The session layer

E．The network layer

Personal firewall is a technology that helps(66)intruders from accessing data on your PC via the Internet or another network, by keeping(67)data from entering or exiting your system.

Hackers do not just target national security organizations for(68): They want your tax returns, network passwords, or bank account numbers. And you do not want the FBI kicking in your door because someone hijacked your PC to(69)in the latest denial-of-service attack on the Internet. Now that "always-on" broadband connections such as cable modems and digital subscriber line are becoming more popular, home users are at risk. Fortunately, you can protect your data. Firewalls can block(70)attacks and protect your PC from outside threats.

A．allow

B．prevent

C．invite

D．get

A. Data, Frame, Packet, Segment, Bit

B. Data, Frame, Segment, Packet, Bit

C. Data, Packet, Frame, Segment, Bit

D. Data, Packet, Segment, Frame, Bit

E. Data, Segment, Frame, Packet, Bit

F. Data, Segment, Packet, Frame, Bit