摘要
The approaches used in organizing and presenting material about the earth and its oceans are as varied as the individuals who undertake the task. Entire books are dedicated to single topics that in themselves form only small parts in the study of the oceanic environment others are devoted to generalized description of the marine system. The choice of approach is governed in part by the purpose for which the material is assembled, the intended educational level, the degree of understanding that is desired, and also by the particular way in which the author himself considers the material.