Iodine and Goiter
Iodine is a well-known example of a trace mineral whose lack in the body creates an easily treated disease. When the thyroid gland is not supplied with sufficient iodine to manufacture hormones, it enlarges and forms a goiter or swelling of the neck.At the same time other symptoms, such as fatigue and sluggishness, weight gain, coldness of the body, and depression, may occur.
In the United States goiter was first noted in the Great Lakes region, where in the 1930s, as many as 40 percent of the people in some areas had goiter, due mainly to iodine-deficient soil. This scarcity had been caused by ice age glaciers melting and washing the iodine out of the soil.
The inhabitants of mountainous regions ofEurope had suffered from iodine deficiency for centuries for similar reasons.
It was discovered in the alpine region of Switzerland in the nineteenth century that in areas in which the drinking water contained less than 0.5 micrograms of iodine per liter there was a high incidence of goiter.
In contrast to mountainous or inland regions, areas by oceans or in the vicinity of ocean breezes usually contain enough iodine to prevent this affliction.
As a fairly accurate rule of thumb, if a map is drawn showing the parts of the world where the water supply is deficient in iodine and then superimposed on a map showing the areas where the inhabitants suffer from goiter, the two mapped areas coincide.
To understand how iodine deficiency leads to goiter, it is necessary to look at the underlying physiology of the thyroid glanD、The human thyroid gland is the only place in the body where iodine is stored, and it requires a daily supply of about 150 micrograms of iodine entering the body. When food or water is digested, the iodine it contains is either taken up by the thyroid or eliminated from the body through the kidneys into the urine. When supplies are low, the kidneys still eliminate iodine from the body so the capacity of the thyroid to preserve an adequate supply of raw material is threateneD、
The thyroid gland consists of thousands of balls of cells, called thyroid vesicles, which enclose a space filled with a jellylike protein called thyroglobulin. These cells have an extraordinary ability to trap iodine from the bloodstream, and the efficiency of this trap can be increased if the amount of iodine in the blood circulation decreases. Once the iodine is trapped by the thyroid vesicles it passes into the thyroglobulin, where the actual manufacture of two kinds of thyroid hormones takes place. The hormones are stored here until they travel back through the thyroid vesicles to enter the bloodstream. The thyroid hormones are then taken to every part of the body where they influence the rate at which the chemical processes of every cell proceeD、They have a pervasive effect on the control of oxygen consumption and heat production of the whole body, and they are essential to the healthy growth of body and minD、
The thyroid tries to keep constant the amount of circulating thyroid hormone entering the cells of the body. When iodine supplies are low, the pituitary gland, a small pea-sized gland at the base of the brain, secretes a thyroid-stimulating hormone (TSH) that in turn regulates the power of the thyroid to trap iodine and increase the output of the thyroiD、If the thyroid is continually stimulated by TSH, the cells get larger and eventually the whole gland enlarges with an increase in the number of its cells. The thyroid may have many temporary crises where iodine supplies are not adequate and where swelling in induced unde

Cultural Shock
"Culture shock" might be called an occupational disease of people who have been suddenly transplanted abroaD、Like most ailments, it has its own symptoms and cure.
Culture shock is precipitated by the anxiety that results from losing all our signs and symbols of social intercourse. Those signs or cues include the thousand and one ways in which we orient ourselves to the situation of daily life; when to shake hands and what to say when we meet people, when and how to give tips, how to make purchases, when to accept and when to refuse invitations, when to take statements seriously and when not.
Now when an individual enters a strange culture, all or most of these familiar cues are removeD、He or she is like a fish out of water. No matter how broad-minded or full of goodwill you may be, a series of props has been knocked out from under you, followed by a feeling of frustration and anxiety. People react to the frustration in much the same way. First they reject the environment which causes the discomfort. "The ways of the host country are bad because they make us feel baD、" When foreigners in a strange land get together to grouse about the host country and its people, you can be sure they are suffering from culture shock.Another phase of culture shock is regression. The home environment suddenly assumes a tremendous importance. To the foreigner everything becomes irrationally glorifieD、All the difficulties and problems are forgotten and only the good things back home are remembereD、It usually takes a trip home to bring one back to reality.
Individuals differ greatly in the degree in which culture shock affects them.
A、[■]Although not common, there are individuals who cannot live in foreign countries.
B、[■]During the first few weeks most individuals are fascinated by the new.
C、[■] They stay in hotels and associate with nationals who speak their language and are polite and gracious to foreigners.
D、[■] This honeymoon stage may last from a few days or weeks to six months, depending on circumstances. If one is very important, he or she will be brought to visit the show places, will be pampered and petted, and in a press interview will speak glowingly about goodwill and international friendship.
But this mentality does not normally last if the foreign visitor remains abroad and needs to seriously cope with real conditions of life. It is then that the second stage begins, characterized by a hostile and aggressive attitude toward the host country. This hostility evidently grows out of the genuine difficulty which the visitor experiences in the process of adjustment. There are house troubles, transportation troubles, shopping troubles, and the fact that people in the host country are largely indifferent to all these troubles. They help, but they don’t understand your great concern over these difficulties. Therefore, they must be insensitive and unsympathetic to you and your worries. The result, "I just don’t like them." You become aggressive, you band together with others from your country and criticize the host country, its ways, and its people.But this criticism is not an objective appraisal.
You take refuge in the colony of others from your country which often becomes the fountainhead of emotionally charged labels known as stereotypes. This is a peculiar kind of offensive shorthand which caricatures the host country and its people in a negative manner. The "dollar graspingAmerican" and the "indolent LatinAmerican" are samples of mild forms of stereotypes. The second stage of culture shock is, in a sense, a crisis in the disease. If you come out of it, you leave before you reach the stage of a nervous breakdown.
If visitors succeed in acquiring some knowledge of the language and begin to get around by themselves, they are beginning to open the way into the new cultural environment. Visitors s

HISTORY OF LANGUAGE
1In evolutionary history, the development of language set humans apart from the rest of the animal kingdom. Spoken language originated when early humans began to string grunts and squeals together to form a sound-meaning system. Language provided humans with the tools to create ideas and then to communicate these ideas to other people.
2 As human knowledge and civilization expanded, a system that stored information became necessary. The first writing systems used pictures to represent objects. These early systems were successful in recording concrete details concerning trade and taxes, but they could not convey abstract ideas and emotions.Between 800 and 500B、
C、, the ancient Greeks began to use a phonetic alphabet that used symbols to represent sounds, with each sound making up part of a wor
D、Thus, written language became a means of mass communication.
3The expansion of humanity from an oral society to one that also used the written word for communication was a defining point in human civilization.Early oral cultures required a tribal mentality with histories defined by family or clan perspectives, but writing allowed a broader, global perspective to emerge.
Look at the four squares,

, and

, which indicate where the following sentence could be added to the passage. Where would the sentence best fit
Before written language evolved, there was no way of permanently recording language.
As human knowledge and civilization expanded, a system that stored information became necessary. The first writing systems used pictures to represent objects.
These early systems were successful in recording concrete details concerning trade and taxes, but they could not convey abstract ideas and emotions.
Between 800 and 500B、
C、, the ancient Greeks began to use a phonetic alphabet that used symbols to represent sounds, with each sound making up part of a wor
D、
Thus, written language became a means of mass communication.

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