Explain set associative mapping

Why should characters such as / \ " ' * ; - ? [ ] ( ) ~ ! $ { } < > # @ & | space, tab, and newline be avoided in file names?

How do you take a green screen out of the video while editing?

An npn transistor is correctly biased and turned on if the a. base is negative. b. collector is negative. c. collector is positive with respect to the emitter and negative with respect to the base. d. collector is the most positive lead followed by the base.