X. Переведите текст с учетом выполненных заданий.

Wide Area Networks

1. A wide area network (WAN) is a computer network that directly connects computers separated by long distance — more than a mile and as much as half the globe. WANs require special media, which are provided by telephone companies and other firms that specialize in this service. WANs also require special hardware.

Physical Media for WANs

3. Wide area networks use special-purpose telephone wires, fiber-optic cables, microwaves, or satellites for communications.

4. The simplest WANs use dedicated lines. A dedicated line is a specially conditioned telephone line that directly and permanently connects two computers. Dedicated lines provided by telephone companies are called private lines, or leased lines. A leased line can handle as much as 64,000 bites per second. Some special-purpose dedicated lines can handle as much as 64 million bits per second.

5. Microwaves, as mentioned earlier, are radio waves that have a very high frequency. Besides warming your pizza, they can transmit data. The chief disadvantage of microwaves id they depend on line-of-sight transmission. No obstruction can get in the way. Furthermore, microwaves can travel only about 50 miles. For both of these reasons, some networks build microwave relay towers.

6. Communications satellites are placed in a geosynchronous orbit thousands of miles above the earth. In this orbit, the satellite rotates with the earth so that it is always above a given spot. The latest WANs use long-distance fiber optic cables.

XI. Составьте аннотацию текста.

Text 11

WAN Service Providers

Просмотрите текст и выполните следующие задания.

I. Используя специализированный англо-русский словарь по вычислительной технике, переведите следующие слова и словосочетания и запомните их:

service provider

common carrier

dedicated Integrated Services Digital Network

value-added network

public data network

data highway (high-speed data highway)

item

multiplexor

unauthorized access

front-end processor

II. Проанализируйте состав слова "usefulness".

III. Используя обычный англо-русский словарь, переведите на русский язык выражение "to get bogged down" и запомните его.

IV. Определите функцию инфинитива в следующем предложении. Переведите предложение на русский язык:

A tariff is a list of services and charges for the services to be offered.

V. Выпишите из первого и четвертого абзацев причастия, определите их форму и функцию и переведите вместе с относящимися к ним словами.

VI. Переведите следующие предложения, обращая внимание на перевод причастия в зависимости от его формы и функции:

1. Architecture including all levels of hardware design is one of the major subdisciplines of computer science.

2. Being equipped with special conversion devices, the hybrid computer utilizes both analog and discrete representation of data.

3. Howard Aiken completed a fully automatic calculator in 1944 using standard machine components.

4. Using the very limited capabilities possessed by all computers, various tasks can be done quite easily.

5. Being based on packet-switching, Asynchronous Transfer Mode was designed with an entirely different approach — cell switching.

6. The data being transmitted from one teletype terminal to another was of great importance.

VII. Помните, что Past Participle может употребляться в причастных оборотах для выражения обстоятельства причины. Такие обороты соответствуют придаточным предложениям причины с глаголом-сказуемым в страдательном залоге. Проанализируйте и переведите следующее предложение из шестого абзаца:

Based on routing data kept in an automatically updated table, the router decides where to send each packet.

VIII. На что указывает "would"в первом предложении седьмого абзаца?