Original sentence: The term "chemtrail" should not be confused with other forms of aerial dumping (e.crop dusting, aerial firefighting, or with the use of smoke trails at airshows; it specifically refers to covert, systematic, high-altitude dumping.— conpiracy site, "NASA Releases Disturbing Picture Of Jet Contrails"
Edited sentence: For this chemtrails special patrons with coloured powders are used that are mounted behind the engine.However Chemtrails are used at aeronautical shows to produce coloured contrails.Video: NASA Releases Disturbing Picture Of Jet Contrails/Chemtrails