Lesson14-Space Shuttle Challenger I. Text Analys Structure Part 1(Paras. 1-6): Preparations of the author before Challenger was launched and the initial liftoff of Challenger Part 2(Paras. 7-19): What the author witnessed during the disaster of challenger Part 3(Paras. 20-21): The author's reaction after the tragedy The end of structure W B TL ELesson14—Space Shuttle Challenger W B T L E Part 1 (Paras. 1—6): Part 2 (Paras. 7—19): Part 3 (Paras. 20—21): I. Text Analysis Structure Preparations of the author before Challenger was launched and the initial liftoff of Challenger What the author witnessed during the disaster of challenger The author’s reaction after the tragedy The end of Structure