问题 单项选择题

在双绞线组网的方式中,以太网的中心连接设备是

A.集线器

B.收发器

C.中继器

D.网卡

答案

参考答案:A

解析: 基于非屏蔽双绞线的以太网结构简单,造价低,组网方便,易于维护,是目前流行的组网方法。在双绞线组网方式中,集线器是中心连接设备,在采用CS MA/CD介质访问控制方法的前提下,通过集线器与非屏蔽双绞线实现了物理上“星”型与逻辑上“总线”型的结构,它是对“共享介质”的总线型局域网结构的一种“变革”。

阅读理解

Do you ever wonder how some things came about? For instance, who figured out that there was something worth eating inside a banana peel? Or how astonishing do you have to be to discover that an artichoke has edible parts? Well, we may not know how either of those foods was discovered, but we do know how potato chips were invented.

Potato chips originated in New England as one man’s variation on the French-fried potatoes, and their production was the result not of a sudden inspiration of cooking invention but of a fit of annoyance.

It was the summer of 1853 and Commodore Vanderbilt, a wealthy railroad magnate, was vacationing at a hotel named Moon Lake Lodge in New York. On the restaurant menu were French-fried potatoes, prepared in the thick-cut French style that was popularized in France in the 1700s and enjoyed by Thomas Jefferson as ambassador to that country.

At dinner one night, Vanderbilt complained that his French-fried potatoes were cut too thick and sent them back to the kitchen. Offended by his snobbyguest, chef George Crum decided he would give Mr. Vanderbilt exactly what he asked for! He decided to annoy the guest by producing French fries too thin and crisp. The chef angrily gathered up some potatoes and sliced them paper-thin. He threw the slices into hot oil to fry, drained and salted them and then personally served the new dish to Mr. Vanderbilt.

Surprised to see the chef in the dining room, the other diners fell into silence and everyone held their breath, waiting for Vanderbilt’s reaction.

Vanderbilt immediately popped a crisp potato slice into his mouth and the loud “Crunch” broke the silence. He continued to crunch away, delighted with his new dish. The plan backfired. Vanderbilt was interested in the browned, paper-thin potatoes. Clapping a surprised Chef Crum on the back, Vanderbilt praised him on the impressive potatoes. And other diners requested Crum’s potato chips, which began to appear on the menu as “Saratoga Chips”, a house specialty. Soon they were packaged and sold, first locally, then throughout the New England area. Crum eventually opened his own restaurant, featuring chips. At that time, potatoes were peeled and sliced by hand. It was the invention of the mechanical potato peeler in the 1920s that paved the way for potato chips to rise quickly from a small specialty item to a top-selling snack food.

小题1:.

The author wrote the first paragraph to         .

A.tell us how potato chips were invented

B.introduce the topic dealt with in the passage

C.give examples of how some things came about

D.explain why we do know how those foods were discovered小题2:.

. According to the passage, chef George Crum         .

A.invented potato chips by accident

B.opened his own restaurant, featuring potatoes

C.served the new dish to Mr. Vanderbilt in private

D.helped promote potato chips to a top-selling snack小题3:.

. The production of potato chips was the result of         .

A.Mr. Vanderbilt’s praise for the new dish

B.Thomas Jefferson’s appreciation of the French Fries

C.George Crum’s anger at Mr. Vanderbilt

D.the invention of the mechanical potato peeler小题4:.

The underlined word “backfired” in the 6th paragraph probably means           .

A.developed in a successful way

B.made a big difference

C.happened in a particular way

D.had an opposite result

多项选择题