____ protects the entire layer or the page items on a layer from being moved, selected, or deleted accidentally.

A(n) ________ converts the flashes of light back into two voltages that can be used by a computer

A) laser diode B) photo detector C) electromagnetic wave D) repeater

What is the difference in a serial interface with a status of down and a status of administratively down?

Status of down means the interface is shut down. Administratively down means the link is lost and probably disconnected. True or False? Indicate whether the statement is true or false