number of daily servings from each group. The NUTRITION article describes these food groups and lists the recommended number of servings. Meals planned according to these guidelines provide the nutrients a person needs without adding extra calories or dietary fat.

Planning appealing meals: An appealing meal includes foods that have contrasting colors, shapes, textures, flavors, and temperatures. The selection of vegetables and fruits can be especially important in adding color to a meal. For example, a meal of sliced turkey, cauliflower, mashed potatoes, white bread, and milk would look unappetizing. A green vegetable and an orange one, instead of cauliflower and potatoes, would make the meal more colorful and appealing. Cutting carrots, beets, and other vegetables into contrasting shapes can also help create variety. The textures of solid foods range from soft to firm, and a meal should include foods that vary in chewiness. Most meals also should include at least one hot food and one cold dish. In addition, a person should serve foods that differ in flavor.

Foods called garnishes can make a dish more attractive. They usually are arranged around the food after it has been cooked. Common garnishes include parsley sprigs, tomato slices, and lemon

DANCE

Dance is the movement of the human body in a rhythmic way. Dance serves many functions in human society. It is an art form, a social activity, a type of communication, and a form of recreation. People can dance by themselves, in couples, or in large groups. The dance can be spontaneous or performed in established movements. It can tell a story, explore an emotion, or serve as a form of self-expression. Many people dance as a career, but anyone can dance simply by moving in rhythm. Dance is among the oldest human art forms. Dancing extends beyond the human species itself. For example, many animals perform complex dances during courtship.

Dance differs from other kinds of rhythmic movement, such as dribbling a basketball, because in dance the movement itself is the goal of the activity. Music usually accompanies dance, providing the rhythm, tempo, and mood for the movements.

In modern societies, many people enjoy dancing simply for entertainment. Each generation creates new dances as an expression of its own sense of life and fun. For example, rock dancing arose about 1960 with the popularity of rock music. This type of dance was created primarily by and for young people. Rock dances such as the twist did not require partners to touch each other while they danced. The dancing was free-spirited and individual, allowing each dancer to create his or her own steps spontaneously. Rock dancing stressed pure emotion underscored by the strong beat of the music.

Why people dance?

Religious reasons - For thousands of years, human beings have danced for religious reasons. Many religions involve some form of dance. Many religious dances are forms of prayer. Believers dance as they pray for rain, for the fertility of crops, and for success in war or in hunting. Such dances often imitate or pantomime some movement. For example, dancers may imitate the movement of the animal to be hunted, or a hunter's actions in stalking it. They may wear elaborate costumes and

masks or makeup to depict deities or animals.

Religious dance also may attempt to create a state of ecstasy (intense joy) or trance in the worshiper. Dance may also be used as one part of a religious occasion or ritual. One example is the dancing of Jews at the festival of Simhat Torah. Another example is the dancing and whirling of members of a Muslim religious order called dervishes. Dancing was a formal element in Christian worship until the A.D. 1100's, when religious leaders began to prohibit it because they believed it was too worldly an activity. However, spontaneous dance has become a common element of worship among some Protestant denominations.

Social reasons - Dancing plays an important role in social functions. All societies have characteristic forms of dance. Such dancing may take place at ceremonial occasions or at informal gatherings. Like traditional foods and costumes, dance helps members of a nation or ethnic group recognize their connection to one another and to their ancestors. By dancing together, members of a group express their sense of common identity or belonging.

Although drama is a form of literature, it differs from other literary forms in the way it is presented. For example, a novel also tells a story involving characters. But a novel tells its story through a combination of dialogue and narrative, and is complete on the printed page. Most drama achieves its greatest effect when it is performed. Some critics believe that a written script is not really a play until it has been acted before an audience.

Drama probably gets most of its effectiveness from its ability to give order and clarity to human experience. The basic elements of drama--feelings, desires, conflicts, and reconciliations--are the major ingredients of human experience. In real life, these emotional experiences often seem to be a jumble of unrelated impressions. In drama, however, the playwright can organize these experiences into understandable patterns. The audience sees the material of real life presented in meaningful form--with the unimportant omitted and the significant emphasized.

No one knows exactly how or when drama began, but nearly every civilization has had some form of it. Drama may have developed from ancient religious ceremonies that were performed to win favor from the gods. In these ceremonies, priests often impersonated supernatural beings or animals, and sometimes imitated such actions as hunting. Stories grew up around some rites and lasted after the rites themselves had died out. These myths may have formed the basis of drama.

Another theory suggests that drama originated in choral hymns of praise sung at the tomb of a dead hero. At some point, a speaker separated from the chorus and began to act out deeds in the hero's life. This acted part gradually became more elaborate, and the role of the chorus diminished. Eventually, the stories were performed as plays, their origins forgotten.

According to a third theory, drama grew out of a natural love of storytelling. Stories told around campfires re-created victories in the hunt or in battle, or the feats of dead heroes. These stories developed into dramatic retellings of the events.

DRAMA/Forms of drama

Among the many forms of Western drama are (1) tragedy, (2) serious drama, (3) melodrama, and(4) comedy. Many plays combine forms. Modern dramatists often disregard these categories and create new forms.

Since prehistoric times, many artists have painted the subjects that were most important to their societies. For example, religion was particularly important in Europe during the Middle Ages, and most of the paintings created then had religious themes.

All great paintings, regardless of subject matter, share a common feature. They do more than just reproduce with paint something that exists, existed, or can be imagined. They also express the painter's special view about a subject.

ACID RAIN

Acid rain is a term for rain, snow, sleet, or other wet precipitation that is polluted by such acids as sulfuric acid and nitric acid. Acid rain harms thousands of lakes, rivers, and streams worldwide, killing fish and other wildlife. It also damages buildings, bridges, and statues. High concentrations of acid rain can harm forests and soil.

Acid rain forms when water vapor in the air reacts with certain chemical compounds. These compounds, including sulfur dioxide and nitrogen oxides, come largely from the burning of coal, gasoline, and oil. Most automobiles, factories, and power plants burn such fuels for energy. Regions affected by acid rain include large parts of eastern North America, Scandinavia and central Europe, and parts of Asia. Since about the 1950's, the problem has increased in rural areas. This has occurred because the use of taller smokestacks in urban areas has enabled the winds to transport pollutants farther from their sources.

Scientists and engineers have developed ways to reduce the acidity of rain. For example, several kinds of devices remove sulfur and nitrogen compounds from fuels or industrial emissions before they reach the atmosphere. Adding lime to lakes and rivers and their drainage areas temporarily neutralizes their acidity. But the neutralization may have harmful side effects.

In 1990, the United States Congress amended the Clean Air Act of 1970 to reduce acid rain in the United States and Canada. The amendments tightened standards for emissions, required fuels that burn more cleanly, and called for power plants to cut their sulfur dioxide emissions.

SUBWAY

Subway is an electric, underground railway designed to move large numbers of people quickly to their destinations. Many systems include railways that are elevated or at ground level. Subways are most useful in crowded urban areas, where heavy traffic often slows down travel by bus or car.

Many of the world's largest cities have or are planning extensive subway systems. London was the first city to have a subway. Today, London has 10 lines that provide quick, cheap transportation to all parts of the city and suburbs. This subway system is often called the tube or the

underground. Some of its subway lines are so far underground that passengers go down on elevators. London's first underground passenger line opened in 1863. It used steam locomotives.

The first deep-level line opened in 1890 and had electric locomotives. All subways since then have used electricity.

Several large cities in the United States have subway systems. Boston was the first American city to have a subway. It opened a line of 11/2 miles (2.4 kilometers) in 1897. The subway in New York City is one of the largest in the world. A person can travel from the New Jersey shore, under the city, beneath two rivers, and into Long Island without seeing daylight. The first sections of New York's subway were opened in 1904. In the United States, subways also operate in Atlanta, Baltimore, Chicago, Los Angeles, Philadelphia, San Francisco, and Washington, D.C. In Canada, subways operate in Montreal and Toronto.

There are three types of subways. One is called the open cut. The construction crew tears out the streets and builds the subways in deep ditches. If two lines are going to cross, the crew digs one roadbed deeper than the other. If the crew lays a pavement or other type of cover over the cut in the ground, the subway is called a cut and cover subway. The third form of subway, which is called a tube, is constructed by boring through the earth at the desired depth without disturbing the

surface. This type of construction is for one or two tracks. The tunnels of an open-cut subway have a rectangular shape. The tunnels of a tube subway are usually circular or semicircular. New York City's subway is mainly rectangular. Much of the London subway is semicircular.

SEWAGE

Sewage is water that contains waste matter produced by human beings. It is also called wastewater. It contains about a tenth of 1 per cent solid matter. Sewage comes from the sinks and toilets of homes, restaurants, office buildings, and factories. It contains dissolved material that cannot be seen, plus bits of such solid matter as human waste and ground-up garbage. Some sewage may also contain ground and surface water runoff that occurs after storms or floods. Most sewage also includes harmful chemicals and disease-producing bacteria.

Most sewage eventually flows into lakes, oceans, rivers, or streams. In the United States, almost all sewage is treated in some way before it goes into the waterways as a semi clear liquid called effluent. Untreated sewage looks and smells foul, and it kills fish and aquatic plants.

Even treated sewage can harm water. For example, most methods used to treat sewage convert organic wastes into inorganic compounds called nitrates, phosphates, and sulfates. Some of these compounds may serve as food for algae and cause large growths of these simple aquatic organisms. After algae die, they decay. The decaying process uses up oxygen. If too much oxygen is used, fish and plants in the water will die.