One of the most fascinating questions about human behavior. is each person is different from all others. The answer to this question would explain the aspect of human nature called personality. Some theories assume that inborn characteristics determine human personality. Many observers have hypothesized (假设) that each person has a dominant temperament, present from birth, which influences his or her behavior. during an entire lifetime. According to one of these theories, people can be classified into four basic types z sanguine, choleric, phlegmatic and melancholic. Each type or temperament is characterized by a unique set of possible strengths and possible weaknesses. Sanguine people are described as the most outgoing of the four temperaments. They are warm, fun- loving, and like the company of others. Because of these strengths, it is said that sanguines often make good salesmen, actors, or public speakers. Sanguines, however, may have some serious weaknesses. Their problems come from their lack of discipline. Easily distracted, they often lack the concentration to complete a job or other people may not trust them. Choleric people are quite different from the carefree, emotional sanguines. Because of their strong will, decisiveness, and productivity, cholerics are natural leaders who are good at making vast plans and motivating other people to help them carry out their plans. They are often successful in business, industry, or politics. Choleric weaknesses can be very damaging, however. Because a strong desire to lead, they can be cruel and cold towards those who do not wish to follow. They often do not listen to advice from others, and once they make a decision, they may become hostile towards anyone who is questioning that decision. Phlegmatics are calm, easy-going people who strive for efficiency and organization. Very diplomatic and polite, they make people feel comfortable and generally help keep things running smoothly. For these reasons, they make good teachers, technicians, etc. Phlegmaties, however, often have weaknesses that keep them from becoming successful. Afraid to take chances, they may avoid taking any steps to improve their position in life. Melancholics are often considered to be gifted persons who possess creative talent. They are very analytical and able to understand complicated processes and to note detail. These people can make good doctors, scientists, artists, writers, and musicians. Melancholics are also said to be loyal, idealistic and self-sacrificing. However, melancholics frequently make themselves miserable because they tend to be negative and critical, and put up inflexible standards. They attach importance to everything they do, so they worry too much and see problems everywhere, and complain too much. They often become disappointed because neither they nor the people around them can live up to their high standards. Explaining human personality in terms of innate temperaments is a theory that has not been generally accepted by psychologists. They criticize it for being too simplistic and unscientific. This may be so: however, present-day psychologists have been unable to formulate a single theory The word 'dominant' probably means______.