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a) ore b) ear c) air

2. Ore always contains ___.

a) all the chemical elements b) some impurities c) only pure metal 3. To get the pure metal metallurgists use special ___.

a) furniture b) furnaces c) solvents

Text 4. How Did the Computer Mouse Come into Being?

The development of the computer mouse as an essential input device followed on the heels of numerous changes to the operating environment of personal computers. Initially, there was no need for a mouse, because there was nothing to point to on a computer screen. Early computers had primitive interfaces that used crude methods to receive data, like punch cards or teletype machines. Once graphical user interfaces were created, however, and pointing became an essential part of interacting with a computer, the mouse soon became the input device of choice in personal computing. The first mouse to have commercial success debuted with Apple’s Macintosh computer in 1984.

Choose one of the options.

1. A mouse is ___.

a) a computer virus b) a system software c) an input device

2.Early computers used ___ cards to receive data. a) punched b) playing c) credit

3.The mouse appeared only after ___ was created. a) a keyboard b) a graphical interface c) a mouse pad

Text 5. What Are the Negative Social Effects of Computer

Addiction?

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Like any other addict, computer addicts can suffer from a variety of harmful side effects from their obsessive behavior. The most common and evident negative side effect revolves around the addict’s social life. Most computer addicts will completely withdraw from their friends and family so they can have more time to spend on the computer, whether e-mailing, chatting, viewing pornography or playing games. Ultimately, the addicts will almost always completely withdraw from their real social world and delve deeper into their cyber world. Gamers, especially, can begin to consider things happening in their virtual gamer’s world as more important than anything in their real lives. Many times these addicts will end up having trouble navigating real social situations.

Choose one of the options.

1. A computer addict is a person who ___.

a) writes computer programmes b) spends most of his time at a computer c) can add well

2. The most important things for computer gamers are those which happen ___. a) in their virtual world b) at their home c) with their football-team mates

Text 6. What Is Lava?

Lava is the molten or melted rock that is forced from volcanoes and cracks within the Earth’s surface, as well as what is left behind once it cools and hardens. Cooled lava has formed many mountains and island chains, and much of it eventually becomes lush and productive soil. Lava is made up of mostly silicon dioxide, and geologists believe magma (the term used to describe the molten rock deep within the Earth) is created under extreme pressure and temperatures at great depths below the Earth’s crust. When a volcano erupts,

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molten rock is forced up through the Earth’s crust and expelled out as lava, which can reach temperatures as high as 2,000 degrees Fahrenheit (1,200 degrees Celsius).

Choose one of the options.

1.Cooled lava formed many ___. a) cities b) islands c) continents

2.Molten rock deep below the Earth’s crust is called ___. a) enigma b) sigma c) magma

3.Volcanic explosion is called ___.

a) corruption b) eruption c) extrusion

Text 7. What do we know about the surface of Mars?

Ever since the first successful flyby over Mars in 1964, scientists have been striving to gather more and more information about our rusty-red planetary neighbor. What we know already, based on soil and rock samples, as well as our observation of the planet, is that Mars is dusty, dry and cold. Its surface is heavily dotted with deep craters in some areas, while other areas have volcanic mountains even higher than Earth’s highest volcano. Mars also has low-lying plains where scientists have discovered evidence of wind streaks, dunes and basins that resemble riverbeds. There are canyons on Mars, far deeper than our canyons on Earth, as well as polar regions – icy caps made up mostly of frozen carbon dioxide. Evidence suggests that liquid water once flowed over the surface of Mars. But as far as we know today, Mars remains a dry, rocky planet pummeled by dust storms and pocked with crater cavities.

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Choose one of the options.

1. The first successful flight over Mars was performed ___.

a) in the late 1960s b) last year c) at the beginning of 20th century

2.Observations proved that Mars is ___. a) cold b) warm c) hot

3.Ice on Mars is made of ___.

a) water b) carbon monoxide c) carbon dioxide

Text 8. What Is An Electric Car?

Active Vocabulary:

An electric car is powered by an electric motor instead of a gasoline engine. The electric motor gets energy from a controller, which regulates the amount of power based on the driver’s use of an accelerator pedal. The electric car (also known as electric vehicle or EV) uses energy stored in its rechargeable batteries, which are recharged by common household electricity.

Unlike a hybrid car – which is fueled by gasoline and uses a battery and motor to improve efficiency – an electric car is powered exclusively by electricity. Historically, EVs have not been widely adopted because of limited driving range before needing to be recharged, long recharging times, and a lack of commitment by automakers to produce and market electric cars that have all the creature comforts of gas-powered cars. That’s changing. As battery technology improves – simultaneously increasing energy storage and reducing

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cost – major automakers are expected to begin introducing a new generation of electric cars.

Electric cars produce no tailpipe emissions, reduce our dependency on oil, and are cheaper to operate. Of course, the process of producing the electricity moves the emissions further upstream to the utility company’s smokestack – but even dirty electricity used in electric cars usually reduces our collective carbon footprint.

Choose one of the options.

1. An electric car is powered by ___.

a) an electric motor b) a diesel engine c) an internal combustion engine 2. Batteries are recharged ___.

a) only at service stations b) from another car c) from household electric grid 3. Recharging a battery now takes ___.

a) little time b) much time c) much work of many people

Text 9. How Bearings Work?

Active Vocabulary:

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Have you ever wondered how things like inline skate wheels and electric motors spin so smoothly and quietly? The answer can be found in a neat little machine called a bearing.

The bearing makes many of the machines we use every day possible. Without bearings, we would be constantly replacing parts that wore out from friction.

The concept behind a bearing is very simple. Things roll better than they slide. The wheels on your car are like big bearings. If you had something like skis instead of wheels, your car would be a lot more difficult to push down the road. That is because when things slide, the friction between them causes a force that tends to slow them down. But if the two surfaces can roll over each other, the friction is greatly reduced.

Bearings reduce friction by providing smooth metal balls or rollers, and a smooth inner and outer metal surface for the balls to roll against. These balls or rollers “bear” the load, allowing the device to spin smoothly.

There are several types of bearings, and each has its own interesting uses, including magnetic bearings and giant roller bearings.

Magnetic Bearings. Some very high-speed devices, like advanced flywheel energy storage systems, use magnet bearings. These bearings allow the flywheel to float on a magnetic field created by the bearing. Some of the flywheels run at speeds in excess of 50,000 revolutions per minute (rpm). Normal bearings with rollers or balls would melt down or explode at these speeds. The magnetic bearing has no moving parts, so it can handle these incredible speeds.

Giant Roller Bearings. Probably the first use of a bearing was back when the Egyptians were building the pyramids. They put round logs under the heavy stones so that they could roll them to the building site. This method is still used today when large, very heavy objects like the Cape Hatteras lighthouse need to be moved.

Earthquake-Proof Buildings. The new San Francisco International Airport uses many advanced building technologies to help it withstand earthquakes. One of these technologies involves giant ball bearings. The 267 columns that support the weight of the airport each ride on a 5-foot-diameter (1.5-meter) steel ball bearing. The ball rests in a concave base that is connected to the ground. In the event of an earthquake, the ground can move 20 inches (51 cm) in any direction. The columns that rest on the balls move somewhat less than this as they roll

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around in their bases, which helps isolate the building from the motion of the ground. When the earthquake is over, gravity pulls the columns back to the center of their bases.

І. Decide which of these statements are true and which are false.

1. Bearings help to prevent wearing of parts caused by friction. 2. The concept of bearing is rolling instead of jumping. 3. Magnetic bearings are used in flywheels. 4. Ancient Egyptians put big stones under logs when they constructed pyramids. 5. Giant ball bearings are used in San Francisco’s Opera House to prevent the building from ruining in earthquakes.

ІІ. Answer the following questions.

1. Why things that slide begin to slow down? 2. At what speed do some flywheels run? 3. Why do magnetic bearing withstand such speeds? 4. How many columns support the building of San Francisco airport? 5. What force moves the columns back to their places after an earthquake?

Text 10. The Properties of Diamonds

Active Vocabulary:

Diamonds are found as rough stones and must be processed to create a sparkling gem that is ready for purchase.

Diamonds are the crystallized form of carbon created under extreme heat and pressure. It’s this same process that makes diamonds the hardest mineral we

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know of. A diamond ranks a 10 on the Mohs Hardness Scale. The Mohs Scale is used to determine the hardness of solids, especially minerals. It is named after the German mineralogist Friedrich Mohs. Here’s the scale, from softest to hardest:

talc – easily scratched by the fingernail; gypsum – just scratched by the fingernail;

calcite – scratches and is scratched by a copper coin;

fluorite – not scratched by a copper coin and does not scratch glass; apatite – just scratches glass and is easily scratched by a knife; orthoclase – easily scratches glass and is just scratched by a file;

quartz – (amethyst, citrine, tiger’s-eye, aventurine) not scratched by a file; topaz – scratched only by corundum and diamond;

corundum – (sapphires and rubies) scratched only by a diamond; diamond – scratched only by another diamond.

Even though diamond is only one level higher on the scale than corundum, diamond can be anywhere from 10 to hundreds of times harder than this class of gems.

It is the molecular structure of diamonds that makes them so hard. Diamonds are made of carbon atoms linked together in a lattice structure. Each carbon atom shares electrons with four other carbon atoms, forming a tetrahedral unit. This tetrahedral bonding of five carbon atoms forms an incredibly strong molecule. Graphite, another form of carbon, isn’t as strong as diamond because the carbon atoms in graphite link together in rings, where each atom is only linked to one other atom.

І. Decide which of these statements are true and which are false.

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1. Diamonds are a form of sodium. 2. Diamond is the hardest mineral we know. 3. Friedrich Mohs was an Italian Physicist. 4. Quartz is harder than gypsum. 5. In diamonds, carbon atoms make a hexahedron unit.

ІІ. Answer the following questions.

1. What physical phenomena influence the creation of diamonds? 2. What property is the criterion for ordering minerals in the Mohs Scale? 3. How many minerals are there in the Mohs Scale? 4. What makes diamond molecules so strong?

Text 11. Are Cell-phones Harmful?

All cell phones emit some amount of electromagnetic radiation. Given the close proximity of the phone to the head, it is possible for the radiation to cause some sort of harm to the 118 million cell-phone users in the United States. What is being debated in the scientific and political arenas is just how much radiation is considered unsafe, and if there are any potential long-term effects of cell-phone radiation exposure.

There are two types of electromagnetic radiation:

∙Ionizing radiation. This type of radiation contains enough electromagnetic energy to strip atoms and molecules from the tissue and alter chemical reactions in the body. Gamma rays and X-rays are two forms of ionizing radiation. We know they cause damage, which is why we wear a lead vest when X-rays are taken of our bodies.

∙Non-ionizing radiation. Non-ionizing radiation is typically safe. It causes some heating effect, but usually not enough to cause any type of longterm damage to tissue. Radio-frequency energy, visible light and microwave radiation are considered non-ionizing.

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On its Web site, the FDA states that “the available scientific evidence does not demonstrate any adverse health effects associated with the use of mobile phones.” However, that doesn’t mean that the potential for harm doesn’t exist. Radiation can damage human tissue if it is exposed to high levels of RF radiation, according to the FCC. RF radiation has the ability to heat human tissue, much like the way microwave ovens heat food. Damage to tissue can be caused by exposure to RF radiation because the body is not equipped to dissipate excessive amounts of heat. The eyes are particularly vulnerable due to the lack of blood flow in that area.

The added concern with non-ionizing radiation, the type of radiation associated with cell phones, is that it could have long-term effects. Although it may not immediately cause damage to tissue, scientists are still unsure about whether prolonged exposure could create problems. This is an especially sensitive issue today, because more people are using cell phones than ever before. In 1994, there were 16 million cell-phone users in the United States alone. As of July 17, 2001, there were more than 118 million.

Here are a few illnesses and ailments that have potential links to cell-phone radiation: cancer, brain tumors, Alzheimer’s, Parkinson’s, fatigue, headaches.

If you are worried about the potential hazards of cell-phone radiation, here are a few ways to reduce your risk:

∙Use a hands-free headset.

∙Use a phone that places the antenna as far away from you as possible.

∙Extend the antenna during use.

∙Limit calls inside buildings.

∙Limit use by children.

І. Decide which of these statements are true and which are false.

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