- Alcohol
Alcohol - Level 3
Alcohol is the oldest drug that is used in Western countries. For thousands of years, people have made alcoholic beverages. These beverages are made by allowing a process called fermentation to occur. Alcoholic fermentation happens when yeasts or bacteria break down the sugars that occur in some liquids, and convert some of those sugars into alcohol.
Many liquids, such as fruit juices, can ferment.
Thousands of years ago, alcoholic drinks were common in the Middle East. However, the Islamic religion forbids alcohol, so very little alcohol is consumed in this part of the world. In European countries, and in other parts of the world, many different kinds of alcoholic beverages are produced and consumed.
In warmer areas of Europe, people make wine by allowing grape juice to ferment. In cooler areas of Europe, people make beer by fermenting liquids made from water and various grains. The process of fermentation is also used to make stronger drinks known as "spirits." These drinks include vodka, whiskey, and rum. The techniques for making good wine, beer, and spirits have been developed over hundreds of years, and require scientific precision. Some people have developed a great appreciation for well-made wine, beer, or spirits, and have become experts about the many different varieties of
these beverages.
Many people appreciate the taste of alcoholic beverages, but many also enjoy the feelings that alcohol causes. Alcohol belongs to a category of drugs called "depressants" because it "depresses" the central nervous system, causing a person to feel less inhibited or restrained. Many people enjoy this feeling, but when a person drinks a lot of alcohol, he or she loses co-ordination, balance, and judgment. Speech may become unclear, and the person may speak too much. Some people become aggressive or depressed. When a person is under the influence of alcohol, the person is said to be drunk.
- Charles Darwin
Charles Darwin - Level 3
Charles Darwin made what might be the most important scientific discovery of all time-
the theory of evolution by natural selection. It was Darwin who first understood how it
was that plants and animals evolved over time to produce new and different species. At
first, this theory faced much opposition, but since that time it has been supported by
evidence from many areas of science.
- Extinctions
Extinctions - Level 3
Ever since human beings appeared on the Earth, we have had a serious impact on other living things. One of the most serious results of the human presence has been the extinction of other species. Since the arrival of humans, many species of animals and plants have died out as a result of human activity.
The extinction of species is a serious problem. When certain species are eliminated, this may disrupt the balance of nature, leading to overpopulation of some species and extinction of others. These changes may have an impact on humans. Also, some of the species that become extinct might have had benefits for human beings. For example, scientists believe that some of the plants growing in rain forest areas might be valuable for treating human diseases. If these plants become extinct as a result of human activity, then these treatments will never be found.
The earliest extinctions caused by humans occurred very long ago. Modern humans emerged in Africa over 100,000 years ago, and some of those people migrated to other parts of the world. When they reached new areas, they found that it was very easy to hunt the large animals, which had not previously been hunted by humans. As these prehistoric people moved into Europe, Australia, and the Americas, they killed large numbers of large animals. Within a few hundred years, many species of animals had become extinct. For example, prehistoric people reached New Zealand less than 1000 years ago, but they soon hunted a huge bird, called the giant moa, to extinction.
With the beginnings of modern technology, several hundred years ago, many other species were driven to extinction. Hunters armed with guns were able to kill vast numbers of animals. In North America, this led to the extinction of bird species such as the passenger pigeon, which had previously been very numerous. Other species were nearly wiped out, such as the large prairie mammals called bison. There were once millions of these animals, but now only a few thousand remain.
Today, many more species of animals and plants are going extinct. Sometimes this happens because of human expansion into areas that are the habitat of certain species.
When people clear a forest, some species may be lost. In the near future, many other extinctions are possible or likely. In some cases, the problem is due to human greed. For example, some people buy ivory that is taken from the bodies of animals such as elephants or rhinoceros. Hunters sometimes kill these animals simply to take their ivory, and the result is a tragic decline in populations.
- Jazz
Jazz - Level 3
One of the most popular forms of music is known as jazz. Each year, hundreds of
thousands of people attend jazz concerts and festivals in cities around the world. Jazz
music, both old and new, is played on the radio and on home stereos.
Two of the most important features of jazz music are "improvisation" and "syncopation."
Improvisation means that music is created spontaneously by the musician during a
- London
London - Level 3
The city of London is one of the most famous cities in the world. In previous centuries,
London was the centre of the British Empire. Today, it is one of the most important cities
of the emerging European Union.
London is located in southeastern England, on the Thames River (pronounced "tems").
The greater London area contains about 12 million people, and the surrounding areas
- Obesity and Nutrition
Obesity and Nutrition - Level 3
For people in many countries, one of the great triumphs of modern life is that there is a great abundance of food. In those places, problems such as starvation and malnutrition are no longer prevalent, and people do not worry about going hungry.
Despite the fact that there is plenty of food in modern countries, people still face many health problems that are related to their diet. One problem is that modern technology has made it possible to produce cheap and tasty food that is not very healthy. This leads to the problem that many people are obese, or very overweight.
One example of this is the "fast food" that is served by many restaurants. This food is often cooked by frying. Fried food contains a high proportion of fat. Also, fast food meals are often very large. When people frequently eat large amounts of fried "fast food," they will likely eat too much fat. This excess can lead to weight gain. Of course, many people enjoy the taste of fried fast food and like to eat it occasionally. However, eating this kind of food too often is bad for one's health.
Another example of health problems caused by modern food products involves soft drinks and other sweetened beverages. These drinks, sometimes called "pop," have a sweet taste that many people enjoy on occasion. However, these drinks contain large amounts of sugar. When people drink soft drinks very frequently, they consume a great deal of sugar. This excess sugar can lead to weight gain.
The weight gain that can result from consuming too much fast food and too many soft drinks can have several harmful effects. For example, people who are very obese have an increased risk of heart disease and of diabetes. Of course, fast food and soft drinks are not the only causes of obesity. Other eating habits may be involved, and so are lack of exercise and genetic factors.
To avoid the health problems that are associated with obesity, it is important that one does not eat too much food. However, this does not mean that one should try to eat as little as possible. People need an adequate amount of food in order to stay healthy. Also, it is important to avoid new "fad" diets that become popular from time to time, because these are often unsafe. Some of the diets that are recommended in popular books do not contain adequate amounts of nutrients, such as vitamins and minerals.
- Preservation of Forests
Preservation of Forests - Level 3
Many thousands of years ago, much of the world's land area was covered in forests.
Since that time, people have needed to clear the forests by cutting down the trees in
order to make room for their farms and cities. Today, forests are still being cleared, and
many people are worried that too much forest area is being lost.
There are many reasons why it is important to preserve forests. One reason is that the
trees inside the forests help to remove carbon dioxide from the air and put oxygen back
- Scotland
Scotland - Level 3
Scotland is the country that is located on the northern part of the island of Great Britain.
The Scottish people are one of the four main nationalities of the British Isles, together
with the English, the Welsh, and the Irish. Scotland and its people have played an
important part in the history of the English-speaking world.
Scotland can be roughly divided into two main regions. The lowland areas, in the
- Soccer
Soccer - Level 3
Soccer is the most popular sport in the world. The basic rules of the sport are simple:
two teams of eleven players try to kick the soccer ball into the opposing team's goal.
Only one player on each team, the goal-keeper, is allowed to touch the ball with hands or
arms. Perhaps part of the reason for the popularity of soccer is its simplicity. The game
requires no expensive equipment, merely a ball and a playing surface, preferably a large
- The Earth Revolves Around the Sun
The Earth Revolves Around the Sun - Level 3
One year is the time required for the earth to travel around the sun. For most of history,
however, people did not know that the earth moved around the sun. Instead, people
believed that the sun moved around the earth.
The old idea that the sun moved around the earth is known as the "geocentric" theory.
This idea was first made famous by an ancient Greek scientist, Ptolemy, who lived in
- The History of Trial By Jury
The History of Trial By Jury - Level 3
In most English-speaking countries, a person who is accused of a crime has the right to
a "trial by jury." In a trial by jury, the guilt or innocence of the accused person is decided
by a group of 12 people, called jurors, who must listen to the evidence about the case.
The idea of trial by jury is over 800 years old, but there was a time when criminal cases
were decided in other ways. Today, many of these methods seem ridiculous and cruel.
Many accused people were forced to undergo a trial by ordeal. There were several
- The Rights of the Accused
The Rights of the Accused - Level 3
In English-speaking countries, the rights of an accused person are taken very seriously.
Over many centuries, laws evolved in such a way that people could not be arrested or
charged without a very good reason.
Of course, every country needs to enforce its laws. This means that police officers are
needed, and so are "prosecutors"-the lawyers whose job is to make criminal charges
- Worries About Physical Appearance
Worries About Physical Appearance - Level 3
Most people would like to have an attractive physical appearance, but some people become very worried about the way they look. This can sometimes lead them to do things that are unhealthy. For example, many women believe that they must be very thin in order to be attractive. They see pictures of fashion models who are very thin and then believe that an attractive woman must look the same way.
However, many men prefer the appearance of women who are not so thin. In order to become thin, some women try to reduce the amount of food that they eat.
When this is taken to an extreme, a woman might eat far too little food to remain healthy. Her weight may become dangerously low, as she tries to become thinner and thinner. This condition is called "anorexia," and it affects many thousands of women in Western countries.
Anorexia is one of several conditions known as eating disorders. Another eating disorder is called "bulimia." A woman who has bulimia will sometimes eat large amounts of food, but then will try to eliminate the food, by vomiting. This is intended to prevent any weight gain, but it is also a very unhealthy behavior.
Unfortunately, some women are concerned about being very thin, but some women have different concerns related to the appearance of their body. For example, some women believe that their breasts are not large enough, and undergo surgery to enlarge their breasts. In this surgery, some artificial substance is implanted inside the breast to make it larger. Many women have had this surgery, but many of them have suffered serious health problems as a result.
In recent years, many men have also become very concerned about their physical appearance. For example, some men believe that they must become very muscular in order to have an attractive appearance. To achieve this appearance, some men use drugs called steroids, which make it possible to gain large amounts of muscle. However, steroids can have very unhealthy side effects. In addition to drugs, some men have used surgery to change their physical appearance. For example, some men have had implants to make their arms, legs, or chest appear larger.