问题 单项选择题

ATM信元中,UNI信头和NNI信头的差别是 (21) 。当网络出现阻塞时,交换机要 (22) ,信元在线路上传输时,ATM信元要装配成传输帧,如果高层没有数据发送,则必须插入空信元或 (23) ,以便将ATM层信元速率适配成传输线路的速率。ATM网络是基于 (24) 方式的数据交换网络,若要实现IP Over ATM,则需要 (25) 技术。

24()

A.虚拟连接

B.电路

C.无连接

D.存储转发

答案

参考答案:A

阅读理解

阅读理解。

     In the mid-1940s, the young ambitious Ruth and Elliot Handler, owned a company that made wooden

picture frames. In 1945, Ruth and Elliot joined their close friend Harold Mattson to form a company that

would be known for the most famous and successful doll ever created. This company would be named

Mattel after Mattson and Elliot.

      In the mid-1950's, while visiting Switzerland, Ruth Handler purchased a German Lilli doll. Lilli was a

shapely, pretty fashion doll first made in 1955. She was originally fashioned after a famous cartoon character

in the West German Newsletter, Build.

     Lilli is the doll that would inspire Ruth Handler to design the Barbie doll (芭比娃娃). With the help of her

technicians and engineers at Mattel, Barbie was born. Ruth then hired Charlotte Johnson, a fashion designer,

to create Barbie's wardrobe. It was in 1958 that the patent for Barbie was obtained. This would be a fashion

doll unlike any of her time. She would be long-limbed (长肢的), shapely, beautiful, and only 11.5 inches tall.

Ruth and Elliot would name their new fashion doll after their own daughter, Barbie.

     In 1959, the Barbie doll would make her way to the New York Toy Show and receive a cool reception

from the toy buyers.

     Barbie has undergone a lot of changes over the years and has managed to keep up with current trends in

hairstyles, makeup and clothing. She is a reflection of the history of fashion since her introduction to the toy

market.

     Barbie has a universal appeal and collectors both young and old enjoy time spent and memories made with

their dolls.

1. What can we know about Barbie from the passage?

A. She was fashioned after a famous cartoon character.

B. She reflects the history of fashion.

C. She was first made in 1958.

D. She was Ruth's daughter's doll.

2. When Ruth and Elliot created the first doll, _____.

A. they had learned about the toy market

B. they asked a fashion designer to help

C. the doll had a universal appeal

D. the doll had created a promising market

3. The Barbie doll is well received because _____.

A. she is always keeping up with fashion

B. she stands for the toy tendency

C. she is popular with children

D. she has a large market in the world

4. Which is the best title for this passage?

A. Barbie Doll-Symbol of Fashion

B. Barbie Doll-Toy of New Time

C. Current Trend of Barbie Doll

D. Birth and Popularity of Barbie Doll

单项选择题