What Is entered into the system as input?

An atom's diameter is about 0.1 nanometer (1×10-9m), and a human hair is about 1×10-3m. how many times greater is a human hair than an atom's diameter? sorry pushed wronf button but this is math

20 points archie wants to use a reflector as he photographs a newlywed couple. what would he consider in his choice? a. shadow and sunny b. homemade and professional c. lamps and boards d. incident and reflected e. neutral density and enhancement

(, urgent need): how do i change my username