Which of the following explains the “sandwich effect” in a presentation?

A.Like in a sandwich, the most important thing in a presentation is the middle part.

B.A presentation begins and ends with the same idea which is well developed in the body.

C.As there are three parts in a sandwich, there are opening, body and closing in a presentation.

D.Opening and closing contain the same elements.

正确答案：A presentation begins and ends with the same idea which is well developed in the body.