O’zbekiston respublikasi oliy va o’rta maxsus ta’lim vasirligi

Вариант №3
BLINDNESS
Being able to see is one of the most valued of all human senses. Some people say they cannot imagine living without the use of their eyes. Yet mill ions of people in the world have limited sight or no sight at all. In the United States, about 500-thousand persons are legally blind. They may have some sight. But by law, they cannot drive a car or operate some machines. '. - '
The eyesight of more than 11-million other Americans is seriously limited. More than six-million others develop some form of eye desease each year. Two of the most common deseases are cataracts and glaucoma-Cataract is a clouding in the lens of the eye. It may become cloudy as one grows older or as a result of desease. The patient receives a plastic lens as a replacement.
Much research is being done. Doctor Peter Cador at America's National Eye Institute said his research showed that cataracts are caused by an enzyme.
Another major cause of blindness is glaucoma. The cause of glaucoma is not yet fully understood. Normally, the fluids move in and out of the eye all the time.
Researcher Harry Quigly at the Johns Hopkins Medical School said glaucoma seems to be caused by a genetic disorder. He also said there is a link between glaucoma and high blood pressure.
Many cases of glaucoma can be treated now.
Researchers have learned that diabetics are more likely than other persons to develop cataracts and glaucoma.
Cataracts, glaucoma and diabetic retinopathy are the most common causes of blindness in industrial countries.
One of the infectious deseases is trachoma. Another is onchocerciacis. It is caused by a virus. It damages the other parts of the eye called the cornea and conjuctiva. Trachoma is most common in developing countries in East Asia, the Middle East and along the Mediterranean Sea. It is rare in industrial countries. Trachoma can be prevented. This can be done by keeping drinking water and living area clean. Trachoma can be cured if discovered early.
The desease onchocerciacis is usually called "river blind­ness". River blindness is passed to humans by the bite of an insect, the black fly. The desease is most common in parts of Africa and Central America.
In addition to trachoma and river blindness, poor nutrition is the most common cause of blindness in, developing countries. A lack of just one vitamin — vitamin A — can mean the dif­ference between blindness and normal sight. A lack of vitamin A leads to the desease called xerophthalmia. Without vitamin A, the eye becomes very dry. Sometimes the eye looks cloudy.
The first sign of a vitamin A disorder is night blindness. Persons suffering from this desease cannot see in low light levels.
Scientists around the world are continuing to study the many causes of blindness, as well as to save our sight. Other scientists are developing technologies to help people who al­ready have lost part or all of their sight.
(From "Science in the News", 1989).
1.Tеkstni uking va tarjima kiling.
2.Tеkstga savollar tuzing.
3.Shu savollarga javoblar bеring.
4.Shu tеkst asosida dialog tuzing.
5.Shu tеkstga moslab xikoya tuzing.
6.Ixtiyoriy 20 gapdan iborat bulgan uzbеkcha matnni ingliz tiliga
tarjima kiling.
7.Tеkstdagi xar bir gapning fе'l zamonlarini aniklang.
8.Tеkstdan modal fе'llar, kuchirma va uzlashtirma gaplar, payt va
shart ergash gaplarini aniklang va ular xakida kiskacha yozing.
9.Sеvimli taomlaringiz, bayramlar, kitoblar, filmlar xakida
bittasini tanlab yozing.
10.Uzbеkistonning bayrogi, gеrbi, Konstitutsiyasi, kadimiy
shaxarlari, sanoat kishlok xujaligi xakida xoxlagan bita tеmani
kiskacha yozing.