{HEAD ~ The projection} of electron beams that are transmitted by the slot apertures and strike the fluorescent screen can be made straight by boring {TAIL ~ slot apertures} in advance that are curved in the direction opposite the curvature of the electron beam projection 
made straight by boring
{ HEAD ~ The projection } of electron beams that are transmitted by the slot apertures and strike the fluorescent screen can be made straight by boring { TAIL ~ slot apertures } in advance that are curved in the direction opposite the curvature of the electron beam projection
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