Aperture is the length of time that light is let into the camera to expose the film.

For #1 i believe the answer would be d. because it is hard to perfect thatfor #3 i believe the answer would be b. because latin root meaning round  for #6 i believe the answer would be a. because it is a jewish thing

Musical notation is a system which is used to  visually represent music  pertaining to the ear  contend  with instruments or sung by the human voice through  the employment  of written, printed, or different symbols.in the western music tradition, the sound is represented in written form through musical notation.in musical notation, the pitch is indicated exclusively by the position of notes on the lines and spaces of the staff.