[单项选择]

For each blank, choose the best answer from the four choices and write down on the answer’sheet.
（） is a protocol that a host uses to inform a router when it joins or leaves an Internet multicast group.
（） is an error detection code that most data communication networks use.
（） is an interior gateway protocol that uses a distance vector algorithm to propagate routing information.
（） is a transfer mode in which all types of information are organized into fixed form cells on an asynchronous or non-periodic basis over a range of media.
（） is an identifier of a web page.

（） is a transfer mode in which all types of information are organized into fixed form cells on an asynchronous or non-periodic basis over a range of media.
A. ISDN
B. X.25
C. Frame Relay
D. ATM

[单项选择]

For each blank, choose the best answer from the four choices and write down on the answer’sheet.
（） is a protocol that a host uses to inform a router when it joins or leaves an Internet multicast group.
（） is an error detection code that most data communication networks use.
（） is an interior gateway protocol that uses a distance vector algorithm to propagate routing information.
（） is a transfer mode in which all types of information are organized into fixed form cells on an asynchronous or non-periodic basis over a range of media.
（） is an identifier of a web page.

（） is a protocol that a host uses to inform a router when it joins or leaves an Internet multicast group.
A. ICMP
B. SMTP
C. IGMP
D. ARP

[单项选择]

In the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet.
Spread spectrum simply means that data is sent in small pieces over a number of the （）frequencies availablefor use at any time in the specified range. Devices using （） spread spectrum (DSSS) communicate by （） each byte of data into several parts and sending them concurrently on different （） . DSSS uses a lot of the available （） , about 22 megahertz (MHz).

Spread spectrum simply means that data is sent in small pieces over a number of the （）frequencies availablefor use at any time in the specified range.
A. continuous
B. high
C. low
D. discrete

[单项选择]What do we know about the author from the first four paragraphs

[单项选择]I suggested that the students each ______a plan for the summer vacation．
A. would make
B. will make
C. make
D. made

[单项选择]It becomes clear from the text that the driving force(动力)behind green products is ______.

[单项选择]Which of the following best describes each of the four women's attitudes towards slimming
(1) Glynis Davis.


A. E． 1-d; 2-d; 3-b; 4-cB. 1-c; 2-b; 3-d; 4-aC. 1-c; 2-d; 3-b; 4-aD. 1-a; 2-b; 3-c; 4-d

[单项选择]This fever will return from time to time, if it follows its usual ______.


A. pattern
B. model
C. mode
D. norm