'Sirs: you know that selenium is a conductor when it is exposed to light, and an insulator in the dark.
Germ, Anyanwụ: bụ akụkụ nke onye na-eme ọrụ na mgbe ọ bụ nwata na-ahụ n'ahụ ahụ pituitary ma nwee ìhè doro anya.