I believe the correct answer is: material that the lens is
made from.
Lenses are engineered to have
specific focal lengths, besides the curvature of the two sides of a lens. The
focal range, the distance between your optic nerve and the retins in lens, of
the lenses is determined by the material that lenses are made from.
Answer:
a literature that is spoken or sung as opposed to that which is written, though much oral literature has been transcribed. There is no standard definition, as folklorists have varying descriptions for oral literature or folk literature.
Explanation:
