If you mix all light colours, do you get black, white or a rainbow?

Jazz evolved slowly from a number of different musical sources..true or false

Silverpoint is a. a technique using the blackish residue of impure carbon obtained by removing water from animal and vegetation substances. b. a technique involving the use of a metal point, and a thin silver wire, popular in the 14th and 15th centuries. c. a printmaking technique born from crayon manner that imitates the appearance of chalk lines. d. a technique used since the 16th century involving a stick filled with either colored or black graphite, a heated mixture of carbon and clay

What does ender ask bean to do? why does he choose bean for this task?