【正确答案】[范文]
   Happiness is very difficult to define because it means so many different things to different people. While some people link happiness to wealth and material success, others feel it lies in emotions and loving personal relationships. Yet others think that having a strong spiritual path, rather than a hand in either the material world or relationships with people, is the only way to true happiness. In my opinion, the definition of happiness may vary from person to person but common factors such as self-knowledge and good health do contribute to one's happiness.
   Even if there are various kinds of happiness for each individual, the first step to achieving it is to have a degree of self-knowledge. A person needs to know who he or she is before being able to know what it is that makes him or her happy. After being aware of what he or she needs for a happy life, he or she can know what to pursue and work hard for.
   Of course, factors such as loving relationships, good health, skills to earn a living, and a peaceful environment all contribute to people's happiness, too. Because of good health, people do not suffer from pain and disease, and thus they have more chances and time to enjoy their life instead of staying in the hospital; skills to earn a living allow people to have the ability to survive and to live rather than starving and always be troubled by the survial problem; people tend to be in a better mood with a peaceful environment. However, this does not mean that people without these conditions cannot be happy. Some people in very bad situations can also live a happy life because their spiritual needs are satisfied.
   Overall, an ability to keep clear perspectives in life is a more essential factor in achieving happiness. By that I mean an ability to have a clear sense of what is important in our lives (the welfare of our families, the quality of our relationships, making other people happy, etc.) and what is not (a problem at work, getting annoyed about trivial things, etc.). Like self-awareness, it is also very difficult to achieve, but the inclusion of these two factors may be the most important for obtaining happiness.

【答案解析】 1.语言表达
   本文长短句结合，行文流畅，语言表达清晰，能够准确表达作者观点。
   ● In my opinion, the definition of happiness may vary from person to person but common factors such as self-knowledge and good health do contribute to one's happiness.
   In my opinion...用于议论文开头明确表达作者观点。
   ● Overall, an ability to keep clear perspectives in life is a more essential factor in achieving happiness. By that I mean an ability to have a clear sense of what is important in our lives (the welfare of our families, the quality of our relationships, making other people happy, etc.) and what is not (a problem at work, getting annoyed about trivial things, etc.).
   By that I mean...用于详细解释前句提到的观点或论据。
   2.逻辑结构
   本文采用层层递进的结构，按照题目所问来组织行文，结构清晰。