Example: The misused words in bold are corrected below the article #1.
1.

One of the many modern fads today is the dying of one's hair. Many teenagers and other young adults enjoy adding unnatural color to their hair. You can do this yourself, or you can go to an expensive beauty salon or hair stylist to have it done. This craze may upset parents, educators, and other middle-aged people, but, actually, no harm is done. The chemicals added to the hair are not health-threatening. In other words, you can't get sick from dying your hair. Young people enjoy the extra color and the extra attention. Dying one's hair is not for everyone, to be sure, but for those who want to, go ahead!

You¡÷They
yourself¡÷themselves
you¡÷they
you¡÷they
your¡÷their
go ahead¡÷they should feel free to do so

Exercises: Correct the words in bold.
1.
Libraries remain the treasure houses they always were. Those who use the Internet on a daily basis cannot imagine why anyone would want to go to a library, but there are many reasons why you should still go there. Not only do libraries contain books old and new (many of these older books are not on-line), but they also contain a large selection of magazines and newspapers, both current and used. You can even use computers these days in the library in order to find information in the library faster. Librarians are professionals who can help the visitor find books and help with research questions in the library. Librarians are not on the Internet, however. A visit to a library today is as useful as it always was.
2.
Dreams have great power although they are nothing. According to scientists, everyone dreams several times every night. Most people, however, do not remember all their dreams; indeed, you seldom remember any of them. When a dream is remembered, it may have no influence or a great affect on us depending on the nature of the dream. Some people are inspired by their dreams to create great works of art; others may solve scientific or mathematics problems which bothered them for a long time. Others may feel fear, amusement, or confusion. Although a dream may seem like nothing at all, it can sometimes really be a significant event in our lives.
3.

Why do people keep pets? As there are so many animals living freely in nature, why do so many people keep one or more pets in their own homes? Perhaps the origin of pets is as old as that of keeping animals for food or work. Though no one knows when animals were first controlled by mankind, it is likely that the dog was among the first. Dogs are intelligent and loyal; they are good hunters; and they make you feel safe and loved. Later, after other larger animals were controlled for their food, skin and fur, and work, perhaps small cats, caged birds, and even fish in small ponds were kept not for any practical reason but for companionship. Whatever the origins of keeping pets, you can be sure they are here to stay.

4.
Is graffiti art or vandalism? Some people consider graffiti a sign that young artistic talent cannot be controlled. It truly overflows from the artist to his environment. Most others, however, are not amused by the choice of "canvas" that graffiti artists choose. These opponents say that painting should be confined to private, not public property. It is fine to draw on paper or canvas, or even on one's own walls in your house, but it is quite another matter to spray paint the walls of museums, libraries, and even subway cars. "There is a time and a place for everything," and most people feel this is especially true of graffiti artists. I couldn't agree more with them.
5.

"Just say no!" is easier said than done. When Mrs. Ronald Reagan, the First Lady of the United States during most of the 1980s, first used this phrase, many parents, teachers, and organizations repeated it and used it in their anti-drug education. The phrase is simple and easy to understand, but, unfortunately, it has little effect. The voices of the drug pushers and the youth who are already taking drugs speak much louder than this simple but ineffective saying. Much more needs to be said before you will be convinced that taking drugs is like taking poison. It seems most of us do not take this or any other well-meant advice easily; otherwise, there would be far fewer problems in the world.

6.

Should teenagers work part-time after their high school classes? Some parents and educators feel that the primary responsibility of students is to study. Classes in Taiwan require a great deal of preparation and homework, these adults say, so teenagers should use their time wisely and study. Others, including many young people, insist that working part-time is an excellent education in itself. Students who work part-time are taught how to manage their time and money better; they learn important business and social skills on the job; and you might even meet friends or "that special someone" at work. We can see how working is good for students.
7.
Should high school students have to wear uniforms? That depends on whom you ask. Some people think that you need to wear one in school to show your pride, but I think there are other, better ways to show our high school pride. Those people say that teenagers should be studying, not showing off how much money we have by buying fashionable clothing. My friends and I think, however, that learning to dress properly for society is very important. Teenagers become young adults quickly as soon as they graduate and enter the workforce. They have to learn how to dress themselves to fit in with others around them. For this reason alone, high school students should not have to wear high school uniforms.
(Note: #7 is hopelessly mixed up! You should adopt either a first/second person stance or a third person stance only for this composition.)