Establishing objective is both important and necessary because（）。

A.it lays foundation for the content and organization of the presentation

B.it helps steer the audience towards destination the presenter wants them to reach

C.the more time the presenter spends on it, the fewer efforts the presenter needs to make in audience analysis

D.it is to a presentation what a map is to a long journey

E.it is the most time-consuming step in preparation processes

正确答案：it lays foundation for the content and organization of the presentation；it helps steer the audience towards destination the presenter wants them to reach；it is to a presentation what a map is to a long journey