1. When online file-sharing programs emerged, the music industry changed forever. Perhaps the first widely-used music file-sharing program was Napster. It allowed users to sign up to use the service at no charge. Then they could download music files from other users all over the world by simply typing in what song or album they wanted. Obviously, this was bad news for music artists and record labels because they weren’t making any profits from downloaded music. Eventually, Napster was shut down. While it later reinvented itself as a paying service, other free music-sharing sites cropped up almost immediately. Even though several sites and individual users have been charged, there are still countless individuals who log onto these sites to obtain free music.
The main problem associated with peer file-sharing sites is

2. Today’s low-fat craze has led many people to assume that all fats are unhealthy, but this is simply not the case. Fat is an essential component of any healthy diet because it provides energy and helps the body process nutrients. While all fats should be consumed in moderation, there are good and bad fats. Good fats are what are known as unsaturated fats. They are found in olive oil, fatty fish like salmon, and nuts. Bad fats are saturated and trans fats. They are found in foods like butter, bacon, and ice cream. Consumption of foods that contain trans or saturated fats should be restricted or avoided altogether.
The main purpose of this passage is to

3. There is a clear formula that many students are taught when it comes to writing essays. The first is to develop an introduction, which outlines what will be discussed in the work. It also includes the thesis statement. Next come the supporting paragraphs. Each paragraph contains a topic sentence, supporting evidence, and finally a type of mini-conclusion that restates the point of the paragraph. Finally, the conclusion sums up the purpose of the paper and emphasizes that the thesis statement was proven.
After the topic sentence,

4. Hibernation in animals is an extremely fascinating phenomenon, one that biologists are not yet close to understanding fully. However, it is quite easy to understand why animals hibernate during the cold winter months. Usually, it is because their food is scarce during this time. Animals that are herbivores will find the winters extremely tough, because all of the vegetation will have died off by the time winter arrives. Hibernation is essentially a way of dealing with this food shortage. Animals like birds rely on seeds and small insects for sustenance. Obviously, these will also be quite scarce in the winter when the ground becomes covered and frozen. Many birds address their upcoming food shortage in a different way: they migrate to warmer areas where their sources of food will be plentiful.
The main reason animals hibernate is

5. The so-called anti-aging industry is worth a staggering amount of money in North America. Women are sold all sorts of creams and ointments, and are promised that these will make them look younger over time. Unfortunately, these claims are entirely false. Lotions cannot penetrate to the inner layers of the skin where wrinkles typically form. Therefore, no over-the-counter creams are effective at erasing lines and wrinkles.
According to the author, the anti-aging industry

6. Wells provide water for drinking, bathing, and cleaning to many people across the world. When wells are being dug, there are several issues that must be taken into account to minimize the chance of potential problems down the road. First, it’s important to be aware that groundwater levels differ, depending on the season. In general, groundwater levels will be higher during the winter. So if a well is being dug during the winter, it should be deep enough to remain functional during the summer, when water levels are lower. Well water that is used is replaced by melting snow and rain. If the well owners are using the water faster than it can be replaced, however, the water levels will be lowered. The only way to remedy this, aside from waiting for the groundwater to be replenished naturally, is to deepen the well.
From this passage, it can be concluded that

7. The Amazon Rainforest is one of the most important ecosystems in the world. However, it is slowly being destroyed. Areas of the rainforest are being cleared for farms and roads, and much of the wood is also being harvested and sold. There are several compelling reasons to protect this area. First, a significant number of pharmaceuticals are made from plants that have been discovered in the rainforest, and it's quite possible there are still important plants that have not yet been discovered. Secondly, the rainforest provides a significant portion of the world's oxygen and also absorbs great amounts of carbon dioxide. Without rainforests, global warming could accelerate.
The main purpose of the passage is

8. Marsupials resemble mammals in a number of ways. For one thing, they are warm-blooded creatures. They have hair, and the mothers feed their young by producing milk. However, one thing that separates marsupials from mammals is that their young are born when they are not yet fully developed. Most are born after only about four or five weeks. They finish their development in the pouch of their mother. Some of the more commonly known marsupials are koalas, kangaroos, and opossums. They are a diverse group, with many members having little in common besides their reproductive traits.
A major difference between marsupials and mammals is

9. Literacy rates are lower today than they were fifteen years ago. Then, most people learned to read through the use of phonics. Today, whole language programs are favored by many educators.
If these statements are true, it can be concluded that

10. The media has done a lot to promote racism in North America. For example, it was found that the majority of crimes discussed on the nightly news featured African American suspects. However, when the total number of crimes committed in North America was examined, it was found that white people were also suspects 50% of the time.
If the above information were true, it could be concluded that

11. Many people believe that how we express our feelings is mainly determined by our upbringing and culture. Undoubtedly, this is true in some cases. In North America, for example, it is customary to shake hands when we meet somebody to express acceptance, whereas in other countries they may simply bow slightly to indicate this. Many feelings, however, are expressed in similar ways by people all over the world. These emotions include fear, anger, happiness, disgust, and sorrow. For example, if a person is experiencing fear, his or her eyes will widen and the pupils will dilate. This reaction is largely involuntary. The finding that people express many feelings in a similar manner, regardless of where they are from, indicates that facial expressions are influenced more by evolution than culture.
Based on the passage, it can be concluded that

12. Those so-called green fuels may not be as environmentally friendly as once thought. For example, producing natural gas is a much more labor-intensive process than producing an equal amount of conventional gasoline. Also, producing natural gas involves burning fossil fuels. Transporting natural gas also involves burning fossil fuels.
A weakness of green fuels is that

13. Planning weddings is tough. One important part of the planning process is choosing bridesmaid dresses. Although there used to be a lot of rules when it came to picking out a color, many of them are not observed any more. However, one that is still observed is that the bridesmaids should not wear the same color as the bride. The most popular colors for bridesmaid dresses in recent years have been white and black.
It can be concluded that

14. A bird’s feathers are extremely important, and when they clean and smooth them, it is known as preening. Birds in the wild preen their feathers on a regular basis. This is true of most captive birds as well, but not all. For example, some birds do not preen their feathers at all. This problem is most common in birds that are taken from their mothers at a very young age. Presumably, the absence of preening is due to the fact that they were never shown how to do it properly. A more common problem among captive birds is excessive preening. Some birds may pull out large numbers of their feathers or bite them down to the skin. It should be noted that wild birds never exhibit this kind of behavior. There are several suggestions about how the problem of excessive preening can be solved. Giving birds baths or placing them in an area that has more activity to prevent boredom are suggestions. However, these measures are often not sufficient to solve the problem.
The purpose of the passage is

15. The importance of a comfortable workspace cannot be overstated. Developing a comfortable work environment is relatively simple for employers. Ergonomic chairs, large computer screens, personal desk space, and some level of privacy are all essential. This involves some expense, but not a great deal. Not surprisingly, employees are happier in this type of environment, but it is the employers who really benefit. Reduced sick time, higher levels of employee satisfaction, higher productivity, and more creativity have all been observed.
The main idea expressed in this passage is

16. When people are conducting research, particularly historical research, they usually rely on primary and secondary sources. Primary sources are the more direct type of information. A primary source is an account of an event that is produced by individuals who were actually present. Some examples of primary sources include a person's diary entry about an event, an interview with an eyewitness, a newspaper article, or a transcribed conversation. Secondary sources are pieces of information that are constructed through the use of other, primary sources. Often, the person who creates the secondary source was not actually present at the event. Secondary sources could include books, research papers, and magazine articles. From the passage it can be assumed that

17. Many people do not know the difference between precision and accuracy. While accuracy means that something is correct, precision simply means that you are able to duplicate results and that they are consistent. For example, if a glass of liquid was 100 degrees, an accurate measurement would be one that was close to this temperature. However, if you measured the temperature five times, and came up with a measurement of exactly 50 degrees each time, your measurement would be extremely precise, but not accurate.
The term accurate results refers to

18. It is natural for humans to have fears, but when those fears are completely irrational and begin to interfere with everyday activities they are known as phobias. Agoraphobia is a serious phobia, and it can be devastating for those who suffer from it. Contrary to popular belief, agoraphobia is not simply a fear of open spaces. Rather, the agoraphobic fears being in a place that he feels is unsafe. Depending on the severity of the problem, the agoraphobic might fear going to the mall, walking down the street, or even walking to the mailbox. Often, the agoraphobic will view his home as the safest possible place to be, and he may even be reluctant to leave his house. Treatments for this condition include medication and behavioral therapy.
An agoraphobic would feel safest

19. Satire is a genre that originated in the ancient world and is still popular today. Although satire is often humorous, its purposes and intentions go well beyond simply making people laugh. Satire is a way for the playwright, author, or television producer to criticize society, human nature, and individuals that he holds in contempt. Satire as we know it today developed in Ancient Greece and Rome. There were three main types. The first, Menippean satire, focused on criticizing aspects of human nature. This was done by introducing stereotypical, one-dimensional characters. Horatian satire can be viewed as gentle satire. It made fun of people and their habits but in a way that was not offensive. Juvenalian satire was written is such a way that the audience would experience feelings of disgust and aversion when they saw the characters and their actions. Some of the most popular satires today are fake news shows, like the Daily Show and the Colbert Report, and satirical comic strips like Doonesbury.
The main purpose of the passage is

20. The Internet has made life a whole lot easier for many people, but being online also brings with it very real risks. Hackers can steal personal and financial information. There are several precautions that computer users can take to minimize the level of risk that is involved with being online. One of the most obvious safety precautions is to purchase a good anti-virus and anti-spyware program. Passwords are also a very important part of online security, and several tips can help users create more secure passwords. First, a password should be something that can easily be remembered, but it shouldn't be something others can guess easily. Your first or last name, phone number, or the name of your street are all bad choices, as people could learn this information quite easily. Longer passwords are more secure, and those that use a mixture of upper- and lowercase letters and a combination of letters and numbers are more secure than those that don't. Finally, passwords should be changed often. This can make remembering them more difficult, but the extra effort is worth the added security.
The main purpose of this passage is to

21. Many people feel that the use of stem cells in research is unethical. However, they fail to realize that such research could lead to cures for some of the world’s most troubling diseases. Diseases like Parkinson’s and MS could possibly be cured through the use of stem cells, and those with spinal cord injuries could possibly walk again. Therefore, it is entirely ethical to engage in stem cell research aimed at easing the suffering of those who have life-altering conditions.
The main purpose of the passage is

22. At one time, the use of leeches to treat medical problems was quite common. If a person suffered from a snake bite or a bee sting, leeches were believed to be capable of removing the poison from the body if they were placed on top of the wound. They have also been used for bloodletting and to stop hemorrhages, although neither of these leech treatments would be considered acceptable by present-day physicians. Today, leeches are still used on a limited basis. Most often, leeches are used to drain blood from clogged veins. This results in little pain for the patient and also ensures the patient’s blood will not clot while it is being drained.
The main purpose of the passage is

23. Howard Gardner was a psychologist best known for developing the theory of multiple intelligences. Basically, the theory states that the idea of general intelligence or overall intelligence is somewhat inaccurate. This is because people often show intelligence in different areas. He argued that there are actually different types of intelligence. One type of intelligence that Gardner identified was interpersonal intelligence. People who possess this type of intelligence relate and interact well with others. Intrapersonal intelligence, on the other hand, implies that people are in touch with their own feelings. They enjoy thinking about theories and developing their own thoughts and ideas. People who have linguistic intelligence learn best by taking notes and reading textbooks. These people usually excel in traditional academic environments, as many academic subjects stress these types of activities. The other types of intelligence are kinesthetic, musical, spatial, and logical/mathematical.
We can conclude from the passage that

24. Feudalism was a type of social system that existed in parts of Europe during the Middle Ages. Essentially, there were several different classes within a feudal society. The king controlled all of the land in his jurisdiction. He divided this land among a few barons. The barons then divided up the land they were given and distributed it to knights. It was then split up again and distributed to serfs, who were the lowest members of feudal society. They were permitted to farm small sections of land, but they had to give a portion of their food to the knights in exchange for this privilege. They also had to give free labor to the knights who allowed them to use their land. Serfs had very few rights; they weren't even allowed to leave their land without permission from the knight who controlled the land. The system of feudalism ended when money began to be used as currency instead of land.
It can be concluded that

25. Before the battle between CDs and MP3s, there was a rivalry during the 1960s between the four-track and the eight-track tape. Four-track tapes were invented in the early 1960s by Earl Muntz, an entrepreneur from California. Later, Bill Lear designed the eight-track tape. This latter invention was similar in size to the four-track tape, but it could store and play twice as many songs. Lear had close ties with the motor company Ford, and he convinced them to include eight-track players in their vehicles, which definitely helped the eight-track tape to achieve a high level of popularity. Soon after, they were introduced into homes, and the four-track tape all but disappeared.
The main difference between the four-track and eight-track tape was