Adrodd fel Amhriodol

' Pyrex glass works (later to become Corning) which made domestic glassware and laboratory glass. '

Dywedwch wrthym pam mae’r cynnwys hwn yn amhriodol *(gofynnol)

Dewis categori *(gofynnol)

Os ‘Arall’ rhowch fanylion (dewisol)

Eich enw (dewisol)

Eich cyfeiriad e-bost (dewisol)

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