THE POSTAGE STAMP
Before the postage stamp, it was difficult to send a letter
to another country. The sender paid for the letter to travel in his or her own
country. Then the person in the other country paid for the other part of the
trip. If a letter crossed several countries, the problem was bigger. Rowland
Hill, a British teacher, had the idea of a postage stamp with gum on the back.
The British Post Office made the first stamps in 1840. They were the Penny
Black and the Twopence Blue. A person bought a stamp and put it on a letter.
The post office delivered the letter, or took the letter to the person. When
the person got the letter, it was prepaid That is, the sender paid for it
earlier. Postage stamps became popular in Great Britain immediately. Other
countries started making their own postage stamps very quickly. However, there
were still problems with international mail. Some countries did not want to
accept letters with the stamps of other countries. Finally, in 1874 a German
organized the Universal Postal System (the UPS). Each country in the UPS agreed
to accept letters with prepaid postage from the other members. Today the
offices of the UPS are only in Switzerland. Almost every country in the world
is a member of this organization. It takes care of any international mail
problems. Today post offices in every country sell beautiful stamps. Collecting
stamps is one of the most popular hobbies in the world, and every stamp
collector knows about the Penny Black and the Twopence Blue.
CARS OF THE FUTURE
What kind of cars will we be driving in the year 2015?
Rather different ones from those that we know today. The next twenty years will
bring greater change in car models than the past fifty years. Tomorrow's cars
will not look like those of today. The most important cause that will lead to a
change in the design of cars will be environmental. That is, tomorrow's cars
will be designed not to cause air pollution. They will be electrically powered;
in other words, they will run on electricity entirely and therefore, be
environmentally clean. Besides the problem of pollution, there is also the
problem of heavy traffic and traffic accidents today. The last two may also be
avoided if computers drive the cars instead of drivers. As a passenger, all you
will have to do will be to get in the car and say where you want to go. The
computer will do the rest and take you there. This, however, will require the
construction of special intelligent roads, as tomorrow's models won't be able
to move on ordinary roads. These roads will contain special strips that can
supply (provide) electrical power to the vehicles as they drive along them. The
special equipment in cars will pick up the necessary fuel during long journeys
from a power source which will exist in the road. As computers - not drivers -
will provide safe driving, there will be fewer accidents; or, maybe, there
won't be any accidents at all.
ORANGES
Everybody loves oranges. They are sweet and juicy. They are
in sections, that is, separate parts, so it is easy to eat them. Some oranges
do not have any seeds, i.e. parts which grow into a new part. Some have a thick
skin but others have a thin skin. The orange tree is beautiful. It has a lot of
shiny green leaves. The small white flowers smell very sweet. An orange tree
has flowers and fruit at the same time. There were orange trees twenty million
years ago. The oranges were very small, not like the ones today. The orange
tree probably came from China. Many different kinds of wild oranges grow there
today. In other words, these oranges grow in nature. The Chinese started to
raise, or grow, orange trees around 2400 B.C.; Chinese art has lovely old
pictures of oranges and orange trees. Farmers in other parts of Asia , such as
India and Pakistan, and the Middle East, learned to raise oranges from the
Chinese. Then they taught the Europeans. The Spanish planted orange trees in
North and South America, called the New World . They took them to Florida
first. Oranges are a very important crop (farm product) in Florida today.
"Orange" is both a fruit and a colour. The colour of oranges is very
beautiful. Therefore, in English we use the name of the fruit for the colour.
COAL
Coal is a hard black substance which we take from below the
surface of the earth and burn as fuel. People have known the burning property
of coal for centuries. We know, for example, that the Chinese used it for
smelting copper (Cu) at least 3000 years ago. In Europe, they started using
coal in the 12th century in England. But people used coal the most after the
invention of the steam engine, during the 18th and 19th centuries. Towards the
end of the 19th century, coal was the leading fuel of the world. Today, coal,
petroleum and natural gas are fuels of equal importance. One advantage of coal
is that we can find it closer to the surface than petroleum and natural gas.
Therefore, we can mine coal: that is, take it from under the earth, less
expensively. A second advantage of coal is that there is more of it than there
is of the other two fuels.
There are four kinds of coal in the world. These are
lignite, subbituminous coal, bituminous coal and anthracite. Lignite gives
little heat and contains about 75% elementary carbon. Subbituminous coal
contains less moisture than lignite and produces (gives out) more heat.
Bituminous coal contains less than 86% carbon. Anthracite is the coal with the
highest carbon content (86 % or more) and gives the most heat. Anthracite also
bums slowly and thus maintains - keeps - a uniform and constant fire. These
properties of anthracite make il the most preferable kind of coal, especially
for domestic uses» in other words, for uses in our homes. One disadvantage of
anthracite, however, is that there is less of it than there is of the other
kinds of coal.
We can use coal
directly in domestic fires, to smelt iron (Fe) in turbines, or to produce steam
in steam engines. Our coal supply is large. There is still lots of coal under
the ground. We'll probably have enough of it for about 400 years.
CONTAINERS
We can find containers in our homes, schools, and places of
work. For example, food and nonfood products are sold in containers. A
favourite container of students and teachers is the wastebasket. Of course,
containers are an important part of many professions: painters, doctors,
biologists, photographers, chemists, and others use many kinds of specialized
containers.
In this short
article, it is not possible to discuss all kinds of containers. Therefore, let
us look at some of the simple and basic containers. We will name them, identify
their shapes and the materials they are made of, and say a few words about lids
and tops.
Cans
A can is a metal
container. It is usually cylindrical in shape, and may have a paper label on
the outside. The name of the product is printed on the label or on the metal
itself. Cans open in different ways, depending on the product. We need a can
opener to open some cans; this utensil cuts the metal. Paint cans have lids.
Beverage cans have a pop top or a ring top. Spray cans have a push-button top.
Cans are durable containers. In other words, they are strong and long-lasting.
Boxes and Cartons
Boxes and cartons are
similar containers. Cartons are usually made of card-board (heavy paper) and,
as a result, are not very durable. Boxes can be made of cardboard, paper, wood,
metal, or plastic. Boxes and cartons have rectangular or square sides. Some of
these containers, such as jewelry boxes and egg cartons, have tops that open
and close with hinges. Other boxes and cartons have removable tops (i.e.,*you
can take these tops off).
Jars
A jar is a glass or ceramic container. It has a wide mouth
(top opening) and no neck. Some jars have tops or covers called screw-on-lids
and others have lids that fit inside the mouth. Some jars (e.g., jars you see
in supermarkets) are very practical because they hold many different products,
and because we can clean them and use them again. Jars are durable but
breakable. In other words, they are easy to break by accident.
THE OSTRICH
The ostrich is the
largest bird in the world. Africa and Arabia are the home of the ostrich, but
we can see one in almost every zoo around the world. It has got wings but they
are very small, so it cannot fly. Some male ostriches can be 2.5m in height and
weigh from 90 to 135 kg. An ostrich has a small, flat head and a very long
neck. Its legs are strong and thick. It is an excellent runner. It can run very
fast - about 40 miles an hour. It is faster than a horse, but it is not the
fastest animal. There are faster animals than the ostrich - for example, the
antelope. The food of the ostrich is plants and some insects. Ostriches leave
their eggs into holes in the sand. Sometimes there are 20 eggs in one hole.
They are white and the largest eggs in the world. The female ostrich looks
after the eggs in the daytime and the male ostrich at night.
POLYMER BATTERIES FOR ELECTRIC VEHICLES
There is an interest in developing electric cars for two
reasons. One reason is that there is only a certain amount of fuel in the world
and ij will eventually finish. Another is that electric cars will not cause air
pollution; i.e. the air will be clean. Why aren't there electric cars on the
roads then?
Although there are trucks, vans and other vehicles which run
on electricity, the auto industry cannot yet produce electric passenger cars in
order to sell on the market. This is because of the batteries in the cars
today. These are lead-acid batteries and they do not provide the necessary
power for an electric car. In other words, the car cannot go a long distance
with such a battery. Besides, you must replace it in time. Most engineers
believe that the lead-acid battery is too heavy and too expensive. Therefore,
scientists have developed another type of battery.
This development may now be the first important step in the
mass production of electric automobiles. The new type is a conductive polymer
battery. It is made of a material which is similar to plastic. However, it has
a metallic appearance and the ability to conduct electricity. This new plastic
battery is three times stronger than the ordinary car battery and weighs less
than 5 kilograms. In addition, car builders can form it into any shape. This
means you can place the battery anywhere in the car; for example, under the
roof, behind the door panels or even under the seat. Besides its capacity to
take various shapes, it is also cheap because of the polymers used.
Several types of
conductive polymer batteries are ready to be tested. One disadvantage is that
the polymer battery can be toxic - it can even kill people; therefore, it must
be insulated well.
Many researchers
agree that it is important to solve the energy problem; so the conductive
polymer battery may be an important first step in electric vehicle development.
They believe that such vehicles will replace the ones which we use today.
Our homes are full of devices - machines - that run on
electricity, but we don't use electricity in our homes only. We need it in
schools, hospitals, banks, factories, etc.. Electricity brings us health and
comfort. For example, at home we use it for heating electric fires, irons and
toasters.
We also use electricity to produce shaft power, i.e., power
that we use to run electric motors. For example, washing machines, refrigerators
and mixers use this kind of power. Also vehicles such as subway trains, trolley
buses and electric locomotives have motors that run on electricity.
There are also some very special lamps that produce
ultraviolet rays and infrared rays. We use both ravs in medical treatments. One
of the most valuable and important uses of electricity is in producing X-rays.
When we look at an X-ray, we can see the inside of the human body, and in this
way the physicians, or doctors, can give a more accurate ; that is, correct,
diagnosis of an illness. In other words, when a doctor looks at an X-ray he.
can tell you what kind of an illness you have.
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