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In 17 5 2, Benjamin Franklin made his textbook experiment with a brass key and a silk kite that he flew in a
thunderstorm to prove that lightning and electricity are the same thing. In 1920, a kite-flying championship
for families and individuals was held in London.
These two seemingly unrelated events underscore the fact that kites can be flown for both pleasure and scien-
tific purposes. For example, in the 1800s weather bureaus flew kites to record temperature and humidity at
certain altitudes. On one occasion, ten kites were strung together and flown at a height of four miles to lift
men and carry cameras aloft.
The kite's ability to fly depends on its construction and the way that its line is attached. The familiar dia-
mond-shaped kite flies when its covered face is aligned against the wind flow. The line attached to the nose
of the kite pulls it into the wind, thus creating the necessary angle for the lift force. If the kite's construction
and the angle of the air stream are correct, the kite will encounter greater pressure against its face and lower
pressure against its back. The difference in the pressure creates a lift that causes the kite to rise until it hangs
level from its bridle. Its angle against the wind should be sufficiently large or small to create maximum lift to
overcome both drag and gravity. The towing point to which the line is attached is important because it sets
the kite's angle relative to the air flow. Although the kite must be headed up and into the wind with a velocity
of 8 to 20 miles per hour, it can maintain its position through a tail, a rudder, a keel, vents, or tassels.
Text 2 Read, translate and retell.
The New Scotland Yard, the most famous police unit in the world, is the headquarters of the Metropolitan
Police in London. The police force in London was established in 1829 under an act of the British govern-
ment. The police station and the office, whose task was to deal with the public, was located at the back of the
Westminster area, where mostly government buildings were located. The police station faced a vacant plot of
land, called Great Scotland Yard. According to one legend, the land was set aside to build a residence for the
kings of Scotland, who frequently visited the city. However, such a house was never constructed. Another
story says that the plot was owned by an Englishman, named Adam Scot, but little proof of this version ex-
ists.
After the police force of London was founded, the building housed the police headquarters from September
29,1829. The entire police division consisted of two commissioners, eight superintendents, 20 inspectors, 88
sergeants, and 895 constables. Together they represented a formidable force, and the 50-room building func-
tioned as an administrative center that dealt with public inquiries, correspondence, and recruitment. By 1887,
the staffing of the police force had grown to about 13,000, and it became evident that the accommodations
had to be expanded. A new building on the Thames Embankment was erected in 1907 and another in 1940.
With the advent of new technology, paramount in police detective work, chemical, electronic, and forensic
laboratories experienced a severe shortage of space. The diversification of police duties led to inevitable
growth in the number of the enlisted men and women. As an outcome, Scotland Yard leased a 20-story office
complex on Victoria Street at Broadway. The ever-expanding headquarters were named New Scotland Yard.
It is curious to note that the vast amount of office space for the Metropolitan Police Force does not have a
police station, but includes a citizens' information room.
Text 3 Read, translate and retell.
Vitamins, taken in tiny doses, are a major group of organic compounds that regulate the mechanisms by
which the body converts food into energy. They should not be confused with minerals, which are inorganic
in their makeup. Although in general the naming of vitamins followed the alphabetical order of their identifi-
cation, the nomenclature of individual substances may appear to be somewhat random and disorganized.
Among the 13 vitamins known today, five are produced in the body. Because the body produces sufficient
quantities of some but not all vitamins, they must be supplemented in the daily diet. Although each vitamin
has its specific designation and cannot be replaced by another compound, a lack of one vitamin can interfere
with the processing of another. When a lack of even one vitamin in a diet is continual, a vitamin deficiency
may result.
The best way for an individual to ensure a necessary supply of vitamins is to maintain a balanced diet that
includes a variety of foods and provides adequate quantities of all the compounds. Some people take vitamin
supplements, predominantly in the form of tablets. The vitamins in such supplements are equivalent to those
in food, but an adult who maintains a balanced diet does not need a daily supplement. The ingestion of sup-
plements is recommended only to correct an existing deficiency due to unbalanced diet, to provide vitamins
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