Basically, it is a guide to industry standardization of proven concepts to be presented in a form most useful to pilots.
基本上，它是一份行业标准化指南，以一种对飞行员最有用的形式提出已证实的概念。
A.This guide is the most useful for pilots, is also industry standardized, and the concepts in it have been supplied basically. B.This concept is the most useful for pilots, is also industry standardized, and the guides in it have been confirmed basically. C.This guide is the most useful for pilot, is also industry standardized, and the concepts in it have been confirmed basically.正确答案C
