As can be seen, three shells are sufficient to convert the gamma and x-ray radiation (and ultraviolet and infrared) mostly to harmless RF energy before all three shells are penetrated.
(three shells; are; sufficient to convert the gamma and x-ray radiation (and ultraviolet and infrared) mostly to harmless RF energy) (three shells; to convert; the gamma and x-ray radiation; ultraviolet and infrared) mostly to harmless RF energy) (all three shells; are penetrated; )
three shells three shells all three shells
are to convert are penetrated
sufficient to convert the gamma and x-ray radiation (and ultraviolet and infrared) mostly to harmless RF energy
the gamma and x-ray radiation ultraviolet and infrared) mostly to harmless RF energy