1. Back to the Drawing Board Unit 1_Lesson 6

2. Word Knowledge Line 1: right write tail taleplane plain air heir Line 2: catastrophe phototelegraphbiography Line 3: calculations spokes track discussion Line 4: valuable baggage improvement performance immensely S1: The battered shed at the launching site was a terrible sight. S2: John Daniels took a photograph just as the Flyer left the ground. S3: The Flyer roared down the narrow track. S4: Their performance showed improvement.

3. Vocabulary calculations (cal-cu-la-tions): mathematical data (pg. 93) erratic (er-ra-tic) unpredictable (pg. 106) elated ( e-la-ted): very happy (pg. 107) descent (de-scent): the process of going down (pg. 97) Stabilize (sta-bi-lize): make steady (pg. 94) Thrust : driving force (100)