Контрольная работа по английскому

I. Перепишите предложения, преобразуйте прямую речь в косвенную, переведите полученные предложения. 1. He explained us: “One of the methods for achieving all-optical switching is by means of liquid-crystal (LC) technology, which can be used to control the polarization of the light beam”. 2. Their engineer asks: “When do you plan to finish the training programme?” 3. He answered: “The maintenance trainer will arrive at the weekend”. 4. They told: “The files are being transmitted but they are not arriving in the same form. The data are being corrupted”. II. Перепишите и переведите следующие предложения, обращая внимание на перевод модальных глаголов и глаголов to have и to be в модальном значении. 1. A digital signal can be transmitted over packet-switched network as easily as a circuit-switched network. 2. Governments should be leading the way to a fundamentally new energy direction based on clean renewable energy, like wind or solar power. 3. The elimination of the voice-frequency has to result in great savings both in primary cost and in maintenance. 4. Diskettes may be considered the most common form of storage. 5. A copy of any data must be kept on separate disk. III. Прочитайте следующий текст и ответьте на вопрос: What is Selcall becoming superseded by? Selective calling Often on a small network system, there are many mobile units and one main base station. This would be typical for police or taxi services for example. To help direct messages to the correct recipients and avoid irrelevant traffic on the network`s being a distraction to other units, a variety of means have been devised to create addressing systems. The crudest and oldest of these is called CTCSS, or Continuous Tone- Controlled Squelch System. A more commonly used system is called Selective Calling or Selcall. This also uses audio tones, but these are not restricted to sub-audio tones and are sent as a short burst in sequence. The receiver will be programmed to respond only to a unique set of tones in a precise sequence, and only then will it open the audio circuits for open-channel conversation with the base station. This system is much more versatile than CTCSS, as relatively few tones yield a far greater number of “addresses”. In addition, special features (such as broadcast modes and emergency overrides) can be designed in, using special addresses set aside for the purpose. A mobile unit can also broadcast a Selcall sequence with its unique address to the base, so the user can know before the call is picked up which unit is calling. In practice many selcall systems also have automatic transponding build in, which allows the base station to “interrogate” a mobile if the operator is not present. Features like this, while very simple, are one reason why they are very popular with organizations that need to manage a large number of remote mobile units. Selcall is widely used, though is becoming superseded by much more sophisticated digital systems.