下列说法正确的是（）
A.岩石圈由地壳组成
B.地幔介于莫霍面和古登堡面之间
C.软流层及其以上部分组成岩石圈
D.地核厚度最薄，只有3400米
参考答案：B
解析：
岩石圈不仅包含地壳而且还包含上地幔顶部（软流层以上）部分，地幔介于莫霍面和古登堡面之间，地核最厚，地壳厚度最薄。
考点：本题考查地球内部圈层的划分及特征。
点评：本题难度较小，解答本题的关键是明确地球的内部结构。依据地震波在地球内部传播速度的变化，地球固体表面以下可划分为地壳、地幔、地核三个圈层。具体分析如下图表所示：
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 many groups of people using the scientific method are mentioned in the passage
A．Three.
B．Two.
C．One.
D．Four.