单项选择题


Development of chemistry
Chemistry did not emerge as a science until after the scientific revolution in the seventeenth century and then only rather slowly and laboriously. But chemical knowledge is as old as history, being almost entirely concerned with the practical arts of living. Cooking is essentially a chemical process; so is the melting of metals and the administration of drugs. This basic chemical knowledge, which was applied in most cases as a rule of thumb (单凭经验来做的方法), was nevertheless dependent on previous experiment. It also served to stimulate a fundamental curiosity about the processes themselves. New in formation was always being gained as artisans improved techniques to gain better results.
The development of a scientific approach to chemistry was, however, hampered by several factors. The most serious problem was the vast range of material available and the consequent difficulty of organizing it into some system. In addition, there were social and intellectual difficulties. Chemistry is nothing if not practical; those who practice it must use their hands, they must have a certain practical flair (鉴别力). Yet in many ancient civilizations, practical tasks were primarily the province of a slave population. The thinker or philosopher stood apart from this world, where the practical arts appeared to lack any intellectual content of interest.
The final problem for early chemical science was the element of secrecy. Experts in specific trades had developed their own techniques and guarded their knowledge to pre vent others from stealing their livelihood. Another factor that contributed to secrecy way the esoteric (深奥的) nature of the knowledge of alchemists (炼金术士). In one sense, the second of these was the more serious impediment (阻碍) because the records of the chemical processes that early alchemists had discovered were often written down in symbolic language understandable to very few or in symbols that were purposely obscure.
Which of the following statements best explains why "the second of these was the more serious impediment" (line 22)

A.Chemical knowledge was limited to a small number of people.
B.The symbolic language used was very imprecise.
C.Very few new discoveries were made by alchemists.
D.The records of the chemical processes were not based on experiments.