Ought to

Глaгол ought to в качестве эквивалента глагола must используется для выражения морального долга или настоятельного совета.

You ought to help your parents. Вы должны помогать своим родителям.

Exercise. Замените данный в скобках модальный глагол подходящим к ситуации эквивалентом. Поставьте его в правильной грамматической форме.

1. Jack and Mike are playing tennis tomorrow. Mike is a very good player but I think Jack (can) win.

2. You (must) read this book. It is very interesting.

3. Nobody (may) take photos in this secret laboratory.

4. Yesterday I (must) leave the meeting because I (must) go to the airport to meet my mother.

5. You (must) send all the documents now. We need them very much.

6. My friends (must) arrive next week.

7. The fire was great but fortunately everybody (can) escape.

8. I’m not working tomorrow so I (must not) get up early.

9. Tomorrow’s conference is very important for your future work. You (must) come.

10. You (must not) believe everything you read in newspapers.

Antenna

Найдите в словаре и запишите транскрипцию следующих слов. Правильно прочитайте данные слова несколько раз вслух и постарайтесь запомнить их произношение

Oscillation, diligent, viable, subsequent, concisely, either, essential, aperture, grind, accept, view, rewrite, surface

Words to be learnt

to conduct - проводить

viable source – жизнеспособный источник

resonant antenna – резонансная антенна

fully yet concisely – полно, но в сжатой форме

essential part – значимая часть

to emerge – возникать, появляться

a new breed – новое поколение

the origin – происхождение, начало

plane subreflector – плоский подрефлектор

grinding -шлифование

surface - поверхность

equation - уравнение

to predict - предвидеть

to cause – заставлять, быть причиной

to accept – принимать, согласовывать

to trace back to – проследить, начиная от

society - общество

to recognize – признавать

to simplify - упрощать

to rewrite – переписать

Text

Antennas have been used for 100 years since Hertz conducted his experiments in the 1880s. First, he had to develop a source of very rapid electrical oscillations. After very careful and diligent development, he had a viable source and detector which formed the basis of the apparatus used in subsequent experiments. Hertz discovered the principles of a resonant antenna. Hertz was not only a brilliant experimentalist but also an extremely good writer. He wrote all his work up into papers which describe fully yet concisely the details of all his experiments. The main papers were collected together and published as a book in 1893.

An antenna is a wire or metal conductor used either to radiate energy from a transmitter or to pick up energy at a receiver. It is insulated from the ground and may be situated vertically or horizontally. Antennas are an essential part of every radio system and the steady growth of radio communications has increased the demand for antennas. The 100year period can be broadly divided into two halves. From the start to the 1930s, the story of antenna development follows in a single chronological path, from Hertz work to the early microwave period to long wave communications and then to short wave communications. Most antenna development in this period was empirical. The 1930s represents a clear break point in the history of radio communications and hence antennas. The uses of radio expanded rapidly and separate subject areas emerged. Radar started, microwaves returned, broadcasting expanded and radio astronomy started. A new breed of antenna engineers used rigorous theory to analyze and design antennas. Each of the areas has its own story to tell and the antennas for each area developed to some extent separately with a common theory linking all types.

Hertz was the first person to develop and use antennas in order to verify the existence of radio waves. But microwave engineers now often design antennas using optical principles. Thus the origin of the large aperture antenna can be traced back to the optical telescope of Newton and others. The first reflecting telescope was proposed by the Scottish mathematician James Gregory in 1663, but it was Isaac Newton who built the first instrument in 1672. This used a spherical main reflector and a plane subreflector to produce a focal point on one side of the telescope. In the same year that Isaac Newton proposed his telescope to the Royal society, George Gassegram proposed a reflecting mirror and a subreflector to refocus the light to a point behind the main reflector. However neither the Gassegram nor the Gregorian telescope was practical until James Short developed a method of grinding nonspherical surfaces in 1740.

The formulation of Maxwell`s Equations and hence the start of antennas theory also came before the classical experiments of Hertz. The research of James Clerk Maxwell was founded on the experimental work of Michael Faraday who discovered electromagnetic induction. Maxwell was a brilliant theoretician who predicted that all changes in electrical and magnetic fields cause waves to be propagated in space and that light was just another form of electromagnetic wave. This was a revolutionary suggestion at that time because the generally accepted view was that the ether behaved as a fluid and Newtonian physics of action-at-a-distance applied. Maxwell first published his ideas in 1862 and subsequently expanded them into a book in 1873. The book is recognized as a classical but it was and still is extremely difficult to follow. It was Hertz and Heaviside who simplified and rewrote the Equations in the form we know today.

Задание I. Поставьте вопросы и ответьте на них, закончив предложения по тексту:

1. An antenna is … (what, where, when)

2. Essential part of every radio system is … (what, where, why)

3. The 100year period can be divided into … (what, how, where)

4. Hertz conducted his experiments … (what, who, when)

5. Hertz discovered … (what, who, where, when)

6. The story of antenna development started … (when, where, what, why)

7. James Gregory proposed … (what, when, where, who)

8. Isaac Newton built … (what, who, when)

9. George Gassegram proposed…(what, who, why, where)

10. A method of grinding nonspherical surfaces was developed by…(what, who)

11. Electromagnetic induction was discovered by…(who, what, why)