甲公司购买一台新设备用于生产新产品A，设备价值为45万元，使用寿命为5年，期满无残值，按年数总和法计提折旧(与税法规定一致)。用该设备预计每年能为公司带来销售收入38万元，付现成本15万元。最后一年全部收回第一年垫付的流动资金8万元。假设甲公司适用企业所得税税率为25%，则该公司最后一年因使用该设备产生的净现金流量为()万元。

TCP/IP(71)layer protocols provide services to the application(72)running on a computer. The application layer does not define the application itself, but rather it defines(73)that applications need--like the ability to transfer a file in the case of HTTP. In short, the application layer provides an(74)between software running on a computer and the network itself. The TCP/IP application layer includes a relatively large number of protocols, with HTTP being only one of those. The TCP/IP(75)layer consists of two main protocol options--the Transmission Control Protocol(TCP) and the User Datagram Protocol(UDP).

A．application

B．transport

C．link

D．network

TCP/IP(71)layer protocols provide services to the application(72)running on a computer. The application layer does not define the application itself, but rather it defines(73)that applications need — like the ability to transfer a file in the case of HTTP. In short, the application layer provides an(74)between software running on a computer and the network itself. The TCP/IP application layer includes a relatively large number of protocols, with HTTP being only one of those. The TCP/IP(75)layer consists of two main protocol options — the Transmission Control Protocol(TCP)and the User Datagram Protocol(UDP).

A．application

B．transport

C．link

D．network

TCP/IP(71)layer protocols provide services to the application(72)running on a computer. The application layer does not define the application itself, but rather it defines(73)that applications need--like the ability to transfer a file in the case of HTTP. In short,the application layer provides an(74)between software running on a computer and the network itself. The TCP/IP application layer includes a relatively large number of protocols, with HTTP being only one of those. The TCP/IP(75)layer consists of two main protocol options--the Transmission Control Protocol(TCP)and the User Datagram Protocol(UDP).

A．application

B．transport

C．link

D．network

A、TCP and UDP port numbers are used by application layer protocols.

B、TCP uses port numbers to provide reliable transportation of IP packets.

C、TCP uses windowing and sequencing to provide reliable transfer of data.

D、TCP is a connection-oriented protocol. UDP is a connectionless protocol.

TCP/IP application layer protocols include the following except ().

A、HTTP

B、FTP

C、UDP

D、Telnet

（71）A．network interface layer, internet layer, transport layer and application layer

B．internet layer, network interface layer, transport layer and application layer

C．network interface layer, transport layer, network interface layer and application layer

D．application layer, transport layer, internet layer and network interface layer

（71）A．network interface layer, internet layer, transport layer and application layer

B．internet layer, network interface layer, transport layer and application layer

C．network interface layer, transport layer, network interface layer and application layer

D．application layer, transport layer, internet layer and network interface layer

（71）A．network interface layer, internet layer, transport layer and application layer

B．internet layer, network interface layer, transport layer and application layer

C．network interface layer, transport layer, network interface layer and application layer

D．application layer, transport layer, internet layer and network interface layer

The TCP/IP stack is a complete set of networking protocols. The OSI Model was meant

to be a standardized way of connecting devices together. and most protocols have some direct

correlation to the OSI Model. The OSI Model has 7 layers. the foruth layer is called(75)

A. physical layer

B. data link Iayer

C.application layer

D.transport layer

● A glue that holds the whole Internet together is the network layer protocol,(71). Unlike most older network layer protocols, it was designed from the beginning with internetworking in mind. Its job is to provide a -(72) way to transport datagrams from source to destination, without regard to whether these machines are on the same network or whether there are other networks in between them.

Communication 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.

An 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