Although the process of professionalisation and specialisation was already well under way in British geology during the nineteenth century, its full consequences were thus delayed until the twentieth century. In science generally, however, the nineteenth century must be reckoned as the crucial period for this change in the structure of science.

　　51. The growth of specialisation in the 19th century might be more clearly seen in sciences such as ________.

　　[A] sociology and chemistry

　　[B] physics and psychology

　　[C] sociology and psychology

　　[D] physics and chemistry

　　52. We can infer from the passage that ________.

　　[A] there is little distinction between specialisation and professionalisation

　　[B] amateurs can compete with professionals in some areas of science

　　[C] professionals tend to welcome amateurs into the scientific community

　　[D] amateurs have national academic societies but no local ones

　　53. The author writes of the development of geology to demonstrate ________.

　　[A] the process of specialisation and professionalisation

　　[B] the hardship of amateurs in scientific study

　　[C] the change of policies in scientific publications

　　[D] the discrimination of professionals against amateurs