A. a reverse ordering will help promote the development of the physical sciences
B. our knowledge of physical systems is more reliable than that of social systems
C. our understanding of the social systems is approximately correct
D. we are better able to investigate social phenomena than physical phenomena
3. The author believes that our knowledge of social systems is more secure than that of physical systems because______.
A. it is not based on personal experience
B. new discoveries are less likely to occur in social sciences
C. it is based on a fairly representative quantity of data
D. the records of social systems are more reliable
4. The chances of the physical sciences being subject to great changes are the biggest because _____.
A. contradictory theories keep emerging all the time
B. new information is constantly coming in
C. the direction of their development is difficult to predict
D. our knowledge of the physical world is inaccurate
5. We know less about the astronomical universe than we don about any social system because ______.
A. theories of its origin and history are varied
B. our knowledge of it is highly insecure
C. only a very small sample of it has been observed
D. few scientists are involved in the study of astronomy
答案：ACDAD