Модуль 5 - Modal Verbs and their equivalents. Многофункциональные глаголы в роли модальных - shall, should, will, would, need, dare (1096809), страница 4

Просмтор этого файла доступен только зарегистрированным пользователям. Но у нас супер быстрая регистрация: достаточно только электронной почты!

Текст из файла (страница 4)

Extracts from different books copied by hand were to be sent by post.27. In order to make the satellite a whole number of highly involved scientific and engineeringproblems had to be solved.28. If radiation is to occur at certain critical frequencies, absorption must also occur there.29. In order to see the molecules separately we must necessarily use radiation with a wavelengththousands of times shorter than that of visible light – or, in other words, we have to useradiation called X-rays.30. As we proceed with the study of chemistry we shall find that the subjects with which we aremost concerned are those which have to do with matter and with energy.31.

You do not need to use this instrument.32. Never getting any support in tsarist Russia, Jabloshkov had to leave his fatherland.33. You need not do it!34. Never getting any support in tsarist Russia, Jabloshkov had to leave his fatherland.35. One has got to protect the environment for the generation next.36. One has got to know the main physical laws.37. One has to remember that gamma rays produce a harmful effect on a living organism.3. Тексты для перевода121. Solar EnergyWe have always used the energy of the sun as far back as humans have existed on this planet. As farback as 5,000 years ago, people "worshipped" the sun.

Ra, the sun-god, who was considered the firstking of Egypt. In Mesopotamia, the sun-god Shamash was a major deity and was equated withjustice. In Greece there were two sun deities, Apollo and Helios.The influence of the sun also appears in other religions – Zoroastrianism, Mithraism, Romanreligion, Hinduism, Buddhism, the Druids of England, the Aztecs of Mexico, the Incas of Peru, andmany Native American tribes.We know today, that the sun is simply our nearest star.

Without it, life would not exist on ourplanet. We use the sun's energy every day in many different ways.When we hang laundry outside to dry in the sun, we are using the sun's heat to do work – drying ourclothes.Plants use the sun's light to make food. Animals eat plants for food. And as we have alreadylearned, decaying plants hundreds of millions of years ago produced the coal, oil and natural gasthat we use today.

So, fossil fuels is actually sunlight stored millions and millions of years ago.Indirectly, the sun or other stars are responsible for ALL our energy. Even nuclear energy comesfrom a star because the uranium atoms used in nuclear energy were created in the fury of a nova – astar exploding. Let's look at ways in which we can use the sun's energy.Solar Hot WaterIn the 1890s solar water heaters were being used all over the United States. They proved to be a bigimprovement over wood and coal-burning stoves.

Artificial gas made from coal was available too toheat water, but it cost 10 times the price we pay for natural gas today. And electricity was even moreexpensive if you even had any in your town!Many homes used solar water heaters. In 1897, 30 percent of the homes in Pasadena, just east of LosAngeles, were equipped with solar water heaters. As mechanical improvements were made, solarsystems were used in Arizona, Florida and many other sunny parts of the United States. The pictureshown here is a solar water heater installed on the front roof of a house in Pomona Valley,California, in 1911 (the panels are circled above the four windows).13By 1920, ten of thousands of solar water heaters had been sold. By then, however, large deposits ofoil and natural gas were discovered in the western United States.

As these low cost fuels becameavailable, solar water systems began to be replaced with heaters burning fossil fuels.Today, solar water heaters are making a comeback. There are more than half a million of them inCalifornia alone! They heat water for use inside homes and businesses. They also heat swimmingpools like in the picture.Panels on the roof of a building, like this one on the right, contain water pipes. When the sun hits thepanels and the pipes, the sunlight warms them.That warmed water can then be used in a swimming pool.Solar Thermal ElectricitySolar energy can also be used to make electricity.Some solar power plants, like the one in the picture to the right in California's Mojave Desert, use ahighly curved mirror called a parabolic trough to focus the sunlight on a pipe running down a centralpoint above the curve of the mirror. The mirror focuses the sunlight to strike the pipe, and it gets sohot that it can boil water into steam.

That steam can then be used to turn a turbine to makeelectricity.In California's Mojave desert, there are huge rows of solar mirrors arranged in what's called "solarthermal power plants" that use this idea to make electricity for more than 350,000 homes. Theproblem with solar energy is that it works only when the sun is shining. So, on cloudy days and atnight, the power plants can't create energy.

Some solar plants, are a "hybrid" technology. During the14daytime they use the sun. At night and on cloudy days they burn natural gas to boil the water so theycan continue to make electricity.Another form of solar power plants to make electricity is called a Central Tower Power Plant, likethe one to the right - the Solar Two Project.Sunlight is reflected off 1,800 mirrors circling the tall tower. The mirrors are called heliostats andmove and turn to face the sun all day long.The light is reflected back to the top of the tower in the center of the circle where a fluid is turnedvery hot by the sun's rays. That fluid can be used to boil water to make steam to turn a turbine and agenerator.This experimental power plant is called Solar II.

It was re-built in California's desert using newertechnologies than when it was first built in the early 1980s. Solar II will use the sunlight to changeheat into mechanical energy in the turbine.The power plant will make enough electricity to power about 10,000 homes. Scientists say largercentral tower power plants can make electricity for 100,000 to 200,000 homes.Solar Cells or Photovoltaic EnergyWe can also change the sunlight directly to electricity using solar cells.Solar cells are also called photovoltaic cells – or PV cells for short – and can be found on manysmall appliances, like calculators, and even on spacecraft.

They were first developed in the 1950sfor use on U.S. space satellites. They are made of silicon, a special type of melted sand. Whensunlight strikes the solar cell, electrons (red circles) are knocked loose. They move toward thetreated front surface (dark blue color). An electron imbalance is created between the front and back.When the two surfaces are joined by a connector, like a wire, a current of electricity occurs betweenthe negative and positive sides.These individual solar cells are arranged together in a PV module and the modules are groupedtogether in an array.

Some of the arrays are set on special tracking devices to follow sunlight all daylong.The electrical energy from solar cells can then be used directly. It can be used in a home for lightsand appliances. It can be used in a business. Solar energy can be stored in batteries to light aroadside billboard at night.

Or the energy can be stored in a battery for an emergency roadsidecellular telephone when no telephone wires are around.Some experimental cars also use PV cells. They convert sunlight directly into energy to powerelectric motors on the car.15But when most of us think of solar energy, we think of satellites in outer space. Here's a picture ofsolar panels extending out from a satellite.2. Wind EnergyWind can be used to do work. The kinetic energy of the wind can be changed into other forms ofenergy, either mechanical energy or electrical energy.When a boat lifts a sail, it is using wind energy to push it through the water. This is one form ofwork.Farmers have been using wind energy for many years to pump water from wells using windmillslike the one on the right.In Holland, windmills have been used for centuries to pump water from low-lying areas.Wind is also used to turn large grinding stones to grind wheat or corn, just like a water wheel isturned by water power.Today, the wind is also used to make electricity.Blowing wind spins the blades on a wind turbine – just like a large toy pinwheel.

This device iscalled a wind turbine and not a windmill. A windmill grinds or mills grain, or is used to pump water.The blades of the turbine are attached to a hub that is mounted on a turning shaft. The shaft goesthrough a gear transmission box where the turning speed is increased. The transmission is attachedto a high speed shaft which turns a generator that makes electricity.If the wind gets too high, the turbine has a brake that will keep the blades from turning too fast andbeing damaged.You can use a single smaller wind turbine to power a home or a school.

A small turbine makesenough energy for a house. In the picture on the left, the children at this Iowa school are playingbeneath a wind turbine that makes enough electricity to power their entire school.We have many windy areas in California. And wind is blowing in many places all over the earth.The only problem with wind is that it is not windy all the time. In California, it is usually windierduring the summer months when wind rushes inland from cooler areas, like the ocean to replace hotrising air in California's warm central valleys and deserts.16In order for a wind turbine to work efficiently, wind speeds usually must be above 12 to 14 milesper hour.

Характеристики

Список файлов лекций