随着人民生活水平的不断提高，我市家庭轿车的拥有量逐年增加.据统计，某小区2007年底拥有家庭轿车64辆，2009年底家庭轿车的拥有量达到100辆.若该小区2007年底到2010年底家庭轿车拥有量的年平均增长率都相同，求该小区到2010年底家庭轿车将达到多少辆？
解：设家庭轿车拥有量的年平均增长率为
，则 
解得：
%，
（不合题意，舍去）
答：该小区到2010年底家庭轿车将达到125辆．
设年平均增长率为x，增长基数为64，增长后为100，增长次数为2，由此列方程求解
设年平均增长率为x，依题意，得64（1+x）2=100，
解得x1=
%，x2=-2.25（舍去），100（1+25%）=125，
答：2010年家庭轿车将达到125辆；
点评：本题考查了一元二次方程的应用．关键是根据题意列出方程或不等式求解，舍去不符合题意的解．
Passage Two
| The social sciences, as the name shows, are the scientific study of the behavior of human beings, both in groups and individually. There is no past or present information of human beings who were not in groups. The groups may be small, like the family, or large, like a city or nation. But in order to reach complete development, man must be a member of a society. It is true that some individuals are more solitary than others. Some, like monks or hermits, may decide, for religious or other reasons, to leave their society and live alone. But these are unusual individuals, and even they can not separate themselves completely from the rest of mankind. A society, then, seems to be the natural environment of mankind. Scholars who study mankind in social organizations are called social scientists. The human behavior which social scientists study is learned behavior. The behavior of the human body as a living organism is studied by the biologist, the biochemist, or the physician. This behavior of man’s physical body is inherited through the genetic development of his species. For example, all physical normal and healthy humans learn to walk as their bodies grow and develop. Social scientists concern themselves with the behavior that man must learn so that he can take his place in a social group. In order to be a functioning member of a group, each member must learn to behave in a way acceptable to other members of that group. The kind of behavior, which must be learned, differs according to the differences among societies. The social scientists are newcomers to academic studies. By the end of the nineteenth century, the natural sciences had developed a method, by which they were able to understand the physical world. By using the scientific method, chemists, physicists, and astronomers, for example, learned a great deal about the universe. It seemed reasonable to apply the same method to the study of man’s social life. Through this kind of study man may learn to understand himself much better. The scientific method is a way of collecting facts in order to describe an existing situation as correctly and completely as possible. The description must consist only of what can be perceived, analyzed, measured, and recorded. Feelings and personal opinions or ideas have no place in scientific description. The facts must be observed and described in such a way that another scientist could repeat the same study and get the same results. |
How does social behavior differ from physical behavior
A．It is learned.
B．It is inherited from our ancestors.
C．It depends on genetic development.
D．It is the same for all human beings.