为清楚理解和准确使用手册各部分的信息，定义必要的符号、缩写和术语。
A.Define symbols, abbreviations and terminology necessary for the clear understanding and precise use of the information presented in various sections of the Handbook. B.In order to understand and use the information in the manual clearly, give the definition to the symbols, abbreviations and terms which are necessary. C.For clear understanding and accurate information about the use of each part of the manual define the necessary symbols, abbreviations and terms.正确答案A
