As a review, and reiterated that the readers know what the author of the communication to readers with contents focused on gathering the essentials from Introduction and the Body.
Was reviewed and repeated the reader know that the author wants the reader to know what communication by focusing Introduction and Body gather ideas from it.
A review and remind the readers know the author want to communicate something to readers know by เนื้อหาเน้น collect the gist of Introduction. And the Body.